Abby was conceived in Italy during a one night stand between her mother, Lana, and her father, Angelo Sorrento. After learning about Angelo winning his court case against the hospital for Bay being Switched at Birth, Lana informed Angelo of her pregnancy, believing that he would want a relationship with his second daughter. Initially, Angelo rejected the idea, fearing that the rebuilding of his relationships with Regina, Bay, and Daphne would be compromised. Later, he came to see the error of his ways and decided he did want to raise his new daughter. However, when Lana became uneasy and tried to get him to sign over his paternal rights before she began to develop romantic feelings for him. When Bay told Lana that Angelo still had feelings for Regina, Lana decided to not put Angelo's name on the birth certificate and take the child without his knowledge, hoping to circumvent his legal rights.
Angelo spent months going from state to state in search of his daughter and finally discovered she had been illegally adopted to a same sex couple, Victor and Leo, who had named her after Victor's grandmother. When Leo left the room to introduce Bay to Abigail, Victor revealed that he knew Lana had purposely left Angelo's name off Abby's birth certificate so she could put Abby up for adoption and then stated that he would prove Angelo was an unfit father in court because he had abandoned Daphne as a child. After discussing the situation with Bay, Angelo and Bay got into a fight when Bay began to wonder if it would be better to let Abby stay with Leo and Victor.
After a paternity test proved that Angelo was Abby's biological father, a judge ruled that custody of Abby should be returned to Angelo and she came to live with him. Angelo and Regina discovered that, like Daphne when she was a baby, the sound of the vacuum cleaner causes Abby to stop crying.
- The Past (Forgotten-Swallowed) revealed Abby is nine-months-old.