Avery was the younger sister to Phyllis Summers, growing up together in Darien, Connecticut. Avery was resentful when Phyllis, the big sister she idolized, left home in her late teens, and never looked back.

After Avery's father George had been accused of bilking people out of their life savings through a living facility, she went to law school to dedicate her life to becoming a lawyer who specialized in helping others who were unjustly accused of crimes. While in law school Avery married and was divorced from a man whose last name was Clark, giving her the authoritative name of Avery Bailey Clark to go with her new career which she began in New York City.

Several years later, in Genoa City, Wisconsin, Sharon Newman was arrested for the murder of Skye Lockhart, and her trial began with the famous Vance Abrams as her attorney. Sharon was found guilty, but her former husband, Adam, arranged an elaborate escape for her from the courthouse. Adam, still trying to clear Sharon's name even after everyone thought she was dead, found the correct erased memory chip that once contained the video of Sharon attempting to save Skye. That same day in New Mexico, Sharon was recognized by the carjacker and arrested while attending a barn dance with her new lover, Sam. Sharon was extradited back to Genoa City, where everyone was shocked that she was still alive. Adam visited her in jail, and he caught her and Sam in an embrace and realized that Sharon had not been faithful to him. Feeling betrayed, Adam threw the memory chip that would have vindicated Sharon into the creek. Sharon was convicted to serve thirty years in prison without parole. Sharon's attorney and Phyllis Newman figured out that Adam was withholding the evidence that would clear Sharon, and Phyllis wrote an article exposing him.

Victor hired famous New York lawyer, Avery Bailey Clark, to handle Sharon's appeal for the murder of Skye Lockhart. Phyllis met Avery, and intrigued by the name and familiar face, looked her up on the Internet. Phyllis discovered that Avery was her younger sister, the child with pigtails and braces who had idolized her, whom Phyllis had left behind when she ran away from home as a teenager. Phyllis went to Avery and told her she wanted her past to stay in the past. Then Phyllis admitted to her friend Michael that Avery was her sister, and he tried to make her understand that he had gone through the same with his brother, Kevin, and how close they were now, then helped her get through preliminary questioning by Avery for Sharon's retrial. Avery had to admit to Sharon her relationship to Phyllis, but Sharon agreed to keep Avery as her attorney. Later, Phyllis went to Avery to make amends, but she rebuffed Phyllis. Then Phyllis's ex-husband and still-lover, Nick, walked in on Phyllis telling Avery that Nick was never to find out that they are sisters. Phyllis explained to Nick that she had lied to everyone about her family so that she could forget them. Nick tried to talk Phyllis into getting to know Avery again, but Phyllis refused. Trying to get to know Avery himself, Nick got Avery to admit that while growing up Avery and Phyllis tuned out the drama of their parents by playing video games together –- just as Nick and Phyllis had done when they had been together.

Daisy Carter turned up in the same prison wing as Sharon Newman, and met Avery Bailey Clark, who took Daisy's case once she realized that Daisy was the mother of a baby with Phyllis' son Daniel. Phyllis was livid when she was served with papers that Daisy wanted visitation with her baby daughter, Lucy, whom Phyllis had legal custody, and that her own sister would turn on her. Daisy demanded that she get to see Lucy once a week, that Phyllis give her some money, and that Avery get her out of prison, or Daisy would sue and Lucy would be given to someone else.

Avery and Sharon finally got through to Adam that he was being unreasonable by not helping Sharon when he knew that she was innocent. Without the memory chip, Adam thought it would help to setup his former lover, Assistant D.A., Heather Stevens. Adam got Heather drunk and had Ricky Williams take compromising photos of them kissing in Adam's room, which Avery could use to get a mistrial. Ricky showed the photos to Phyllis in hopes of landing a story and a job where she worked at Restless Style. But once Ricky got to know his half-sister Heather better and realized that she had grown up without their father too, and was quite psychologically damaged from her abusive stepfather, Ricky declined to sell them, and only gave the photos to Avery as a last resort to save Sharon.

Meanwhile, Phyllis spotted a memory chip in the evidence dredged from the creek for the Diane Jenkins case on Detective Ronan Malloy's desk, and they played it. Just as Avery was about to expose Heather to get the mistrial, Ronan and Phyllis burst into the courtroom, and were allowed to present their evidence. After hearing the audio of Sharon trying to save Skye, the judge left it up to the D.A.'s office. Heather dropped the charges against Sharon, and Sharon was given time served for the escape and was set free. Sharon thanked Ronan, but Phyllis made sure that Sharon knew it was Phyllis who had found the chip, and had saved her. Phyllis stole the photos of Heather and Adam from the courtroom and put them up online with a sensational story about the A.D.A. fraternizing with a witness. Heather was fired as A.D.A. as a result. Ricky filed a lawsuit against Phyllis and Restless Style for using work without payment, with Avery representing him, and Avery filed a criminal complaint for theft of evidence from an attorney in court. Nick was livid with Phyllis for once again doing a sensational story without thinking of the collateral damage to other's lives. Phyllis reacted by having sex with Ronan at the police station, and Nick retaliated by having sex with Avery. Phyllis went to warn Nick about some evidence that Ronan had against him, and walked in on Nick and Avery, realizing they had obviously just had sex together. Phyllis had it out with Nick, whom she told to go to hell, and that she would never try to help him again.

Afterward, Phyllis sought out Avery who informed her that she was staying in town permanently. They argued, and Avery brought up that their father's run-in with the law, and that Phyllis had taken sides against him. Later Phyllis was arrested by Ronan for stealing the photos. Daisy called Daniel from prison to let him know that Avery was his aunt and that she was helping Daisy get out of prison and to get their daughter, Lucy, back. Daniel confronted his mother about never knowing that she had a sister, but Phyllis refused to discuss it, so he went to Avery for more information but got none.

Nick confronted Avery about using him to get back at Phyllis. She later apologized to Nick for taking the opportunity to get back at Phyllis without considering the consequences to Nick. Nick forgave Avery, and they went to her room to make love.

On Thanksgiving, Phyllis gave Daisy her allotted time with Lucy. Avery arrived as she was leaving, but the prison went into lockdown, and they were trapped there together. Reminded that it had been Thanksgiving Day when Phyllis had left their home all those years ago, Avery tried to lay a guilt trip on Phyllis about it. Phyllis protested that their dad was a liar, thief, criminal, and master manipulator; and that their mother had brain washed Avery into believing that he was innocent. Phyllis declared that she had been pushed out by their mother, because Phyllis knew the truth and was made to feel like she was the liar and her dad the victim. Phyllis called Avery sanctimonious, and asked why Avery the hot-shot lawyer, had never tried to get her own father out of prison. Avery, in tears, was forced for the first time to admit that she knew their father had been guilty. Phyllis tearfully offered an "olive branch", but Avery just walked out.

It wasn't long before Nick discovered Phyllis writing a story that practically accused Nikki of murdering Diane Jenkins, but this time he fired her. Before Phyllis left town with Lucy to clear her head, she told Avery that Nick may be Avery's now, but not to try to take over the rest of Phyllis' life. Nick and Avery resumed their relationship, which was mostly spent in bed.

On New Year's Eve 2011, Nick danced with his date Avery, but couldn't take his eyes off Phyllis who was dancing and necking with Ronan while watching Nick. After Phyllis took Ronan back to her place, Avery accused Nick of not being over Phyllis, saying that she had promised herself she would never be second best to Phyllis again, and called off their relationship. Meanwhile Ronan was accusing Phyllis of using him to taunt Nick, and left her alone at her penthouse. Nick arrived awhile later, their eyes locked, and he and Phyllis made love.

Avery was called in by Victor to assist Michael Baldwin in defending Nikki Newman for killing Diane Jenkins in self-defense, but Nikki ended up not being charged.

Avery was with Phyllis when Avery received a call from their mother that their father had heart attack and was in critical condition. Avery left for Ohio, but Phyllis refused to go with her. After Avery returned, telling Phyllis that their father was dying, Avery retaliated by trying to get Daisy out of prison and to get Daisy custody of Lucy. Phyllis confided in Nick that she was torn, as she had been the one to turn her father in and send him to prison. Nick recalled how he and Victor had painfully gone to see Victor's estranged father before Albert died, and convinced Phyllis to go to Darien and see her father one last time. And just like Albert greeted Victor, George greeted Phyllis with, "What the hell are you doing here?"

Meanwhile Daisy's hearing for a reduced sentence began, with a key piece of evidence, a video which Ryder had made of Daisy pleading with Sarah Smythe for mercy for Lauren and Jana when they had held them captive. Michael cross-examined Daisy, asking why Daisy never called for help or let them go when Sarah wasn't there, and his closing statement begged the judge not to fall for Daisy's supposed rehabilitation. But Daisy was given time-served and put on parole with psychological counseling. Unable to contact Phyllis, Michael called Daniel who went to Phyllis' penthouse and discovered Daisy already there with Lucy. Daniel tried to reason with her that she was only using Lucy, but Daisy claimed that she wanted to be a good person and good mother, and needed Lucy to love her.

George told Phyllis to go home, that she had ruined him, and if she hadn't blown the whistle on him, he could have repaid his investors. Phyllis countered that she came to him first but he had lied to her, and even knowing that her family would turn against her, she turned him in because she didn’t want a conman for a father. Phyllis begged George to tell the truth before he died to give her peace of mind. With Avery listening outside the door, George admitted that he had bilked his clients out of their life savings. George tried to cover but Avery finally realized that Phyllis had been right about him all along, and Avery told him how disappointed in him she was. Avery and Phyllis left his room to talk, and Avery realized that even their mother knew the truth as George died alone. Avery begged Phyllis to forgive her, saying the past was over, and they didn’t have to hurt each other anymore. Phyllis softened toward her, but said it was too late now that Avery had gotten Daisy released from prison, and declared war if Daisy got custody of Lucy. Daniel arrived after George had died and his mother and aunt had left, but he went through a box of George's things, finding photos of Phyllis and Avery as children. No one attended George's funeral. As executor, Avery paid claims from her father's estate to the people whom he had bilked, which left nothing but an envelope bearing the name 'Phyllis'. Phyllis reluctantly opened it to find Black Beauty, the book that George used to read to her when she was a child, but Phyllis refused to be swayed by the gesture.

Avery refused to represent Daisy anymore, but Daisy went to a judge to return her parental rights, brought a police officer along to seize Lucy from Phyllis, and later got a restraining order against Phyllis. Daniel was finally convinced to claim his parental rights to Lucy to keep her from growing up with Daisy, and both Avery and Michael represented him in court. Daisy was encouraged, and assumed that she and Daniel would end up together and become a family, so she gave her consent. After the hearing Daniel told Daisy that she was delusional, that she had just helped him to be able to sue for custody.

The SEC began an investigation of the Beauty of Nature sale, and Victor gave Michael instructions to handle it. But when Lauren was arrested, Michael went to Lauren's rescue, forgetting the note with the SEC contact that he was supposed to see to help Victor. By the time Michael remembered Victor, it was too late and Victor fired him for causing the loss of millions of dollars. Avery went to work for Victor instead.