Alexandria Forrester was the daughter of Thorne Forrester and Darla Einstein. Through a misunderstanding between Thorne and his ex-wife, Macy Alexander, regarding Macy's estranged husband, Lorenzo Barelli, Thorne got drunk and slept with Macy's best friend, Darla, though he thought he was making love to Macy. The encounter ruined Darla's friendship with Macy, and Darla wanted an abortion, but Thorne talked her out of it. When Macy died later that year, Darla named her daughter Alexandria in honor of Macy. Thorne and Darla got married and happily raised Alexandria.
One night, Darla was helping Phoebe Forrester change a flat tire on a foggy highway when Darla fell into the path of an oncoming car. Alexandria was devastated by her mother's death, but was comforted by Phoebe's mother, Taylor Hayes. Little Alexandria was even the catalyst in healing the decades-old rift between her grandmother, Stephanie Forrester, and her great-grandmother, Ann Douglas.
Eventually, Thorne and Taylor had become a couple, and were planning their wedding. During Alexandria's play date with Hope Logan, Hope innocently told Alexandria that a classmate had said Taylor was driving the car that killed Darla. It was true: Taylor had been drinking but raced to help Phoebe anyway, and hit Darla due to the fog and Taylor's impaired response time. Alexandria ran away, and a sober Taylor went after her, almost hitting Alexandria on the same foggy highway. Little Alexandria couldn't understand how Thorne could marry Taylor, the woman who killed her mother, and blacked out pictures of Taylor with a crayon. On Taylor's wedding day, Taylor went to put on her dress, only to find it ripped to shreds. Thorne and Taylor called off the wedding, realizing that Alexandria wasn't going to accept their relationship.
Thorne continued raising Alexandria as a single parent, with Alexandria only seen on holidays and special occasions. In 2013, Alexandria resurfaced as Aly, a college student who had come home needing to complete an independent survey. Thorne and Aly's grandfather, Eric Forrester, put Aly to work at Forrester. The earthy Aly enjoyed a close relationship with her father, grateful he had devoted so much time to raising her, and spoke of the recent encouragement she had gotten from Sally Spectra, longtime friend to her deceased mother, Darla.
After Thorne sold the beach house where Aly was raised, they moved into the Forrester mansion with Eric, and Aly was instructed to "shadow" her childhood friend, Hope, who had become very successful at Forrester. Aly was awed to see Hope juggling two "hot guys": her on-again-off-again paramour, Liam Spencer, and Liam's half-brother, Wyatt Fuller.