Pilar is the fifty-something matriarch of the Lopez-Fitzgerald family. She was born in Mexico, but moved to Harmony in her twenties as the young wife of Martin Fitzgerald, whom she married when she was eighteen. She immediately got a job working for the wealthy Winthrop family, becoming Ivy's personal maid when Ivy was only a small child. When Ivy wed Julian, Pilar went with her to the Crane household.
Martin disappeared shortly after Pilar gave birth to their youngest daughter, Paloma, leaving her with five children between infant and age ten. Pilar immediately sent Paloma to Mexico to live with and be raised by her sister Maria, leaving grade-school-aged Antonio and Luis in charge of toddlers Theresa and Miguel. At the same time, the young family was also kicked out of their home (they had been living on the Crane grounds). So Pilar had to work two jobs to support her family. This worked for many years, until Antonio ran away from home shortly after high-school, and for many years it was unknown if he was dead or alive.
Although Pilar has always been loyal to Ivy (keeping the secret about Ethan's paternity), her first loyalty is to her family. She knew Theresa was stalking and scheming to break up Ethan and Gwen, but did nothing to stop her daughter. Nor did she take any preventative methods when she learned that Theresa had been snooping and had come across the papers that proved that Ethan was Sam Bennett's son. Even when Theresa lied outright to her employer and her son, Pilar kept quiet.
With the secret about Ethan finally out in the open, Pilar tried hard to keep Ivy from interfering in Sam and Grace's marriage. It soon became clear where her loyalties lay when she learned that Ivy was prepared to tell her son the truth about Theresa. Rather than risk her daughter being exposed for her actions, Pilar attacked the wheelchair bound Ivy, leaving her locked in her room without any means of escape so that Theresa would be able to marry Ethan without interference. Unfortunately, Ivy was able to tell her son the truth.
Pilar lost her job at the mansion a few times, but always came back until Theresa was finally ousted as being an imposter heir to the throne. They were later evicted from their home, and Pilar became very ill, eventually being hospitalized. A mystery cure seemed to be helping her, but after she learned of Antonio's death, she relapsed. Pilar seemed to finally be cured, and then Martin returned to town. Initially Pilar was overjoyed, but upset to learn of Martin's many-years affair with Katherine Crane, whom he had been forced to flee with after Alistair threatened to kill his entire family.
Pilar wasn't willing to let her husband go, though, and was determined to get him back. She even aligned herself with Alistair at one point, but was unable to use the information that he gave her in order to force Martin to be with her. Martin finally confessed to Pilar about why he had left town, and Pilar admitted that she knew -- she knew about Alistair raping Katherine, about the beatings, about Martin helping Alistair cover up Sheridan's murder of her aunt Rachel -- she knew it all.
Martin and Pilar began planning for their life together, and things only seemed to get better when they discovered that Rachel was alive after all, meaning that Martin hadn't really helped cover up a murder. Martin and Pilar moved forward with their future, planning an elaborate vow renewal. Unfortunately, Pilar discovered Martin and Katherine together just hours before the ceremony and told Martin to get out of her life, even though he swore that she was the only one that he wanted.