In 2018, Madeline Reeves revealed to Valentin Cassadine that her daughter's child, believed to have died when Nina had been drugged and had slipped into a coma two decades earlier, was alive and hidden with an adoptive family. According to Madeline, Nina had given birth to a baby girl. Shortly after her confession to Valentin, Madeline died in prison, but she left a box of personal mementos to her daughter, including a necklace with a pendant in the shape of half a heart. Nina was certain that the necklace was a message from her mother.

As a child, Nina's parents had taken Nina to see Annie on Broadway. Nina had fallen in love with the musical and would sneak into her mother's bedroom to retrieve a necklace with a heart-shaped pendant because it had reminded her of the locket in the musical. Nina was certain that the missing half of the pendant was significant. She felt vindicated when Valentin shared Madeline's shocking secret. He added that he had started the search by asking Nina's close friend Curtis to help him track down the child that Madeline had given up for adoption on the black market.

On September 18, 2018, Curtis Ashford located a woman that he believed might be Nina's daughter. Curtis met with Sasha Gilmore and told her about his suspicions, but Sasha denied being adopted. However, Sasha's mother had passed away, so Curtis persuaded Sasha to have a DNA test because he was certain that it would confirm that Sasha was Nina's daughter. On October 1, 2018, a DNA test revealed that Sasha was Nina's biological daughter. A few days later, a second DNA test reported the same results.

On October 11, 2018, Sasha arrived in Port Charles to meet Nina. Sasha claimed that she had only been looking for closure, not a relationship with Nina. Nina couldn't hide her disappointment, so Sasha agreed to extend her stay. Nina was curious if Sasha had the other half of the heart pendant, but Sasha had no idea what Nina was talking about. Nina didn't press it, and happily introduced Sasha to Sasha's half-sister, Kiki Jerome. Kiki was Silas' love child with Ava Jerome.

Sasha and Kiki initially hit it off, but Sasha's attraction to Kiki's boyfriend, Griffin Munro, caused tension. Further complicating matters was a secret that Sasha and Valentin had been keeping -- Sasha was not Nina's biological daughter. Valentin had hired Sasha to pose as Nina's daughter in an effort to win Nina back. Sasha had initially thought the gesture romantic, but she slowly had a change of heart the more she got to know Nina because she realized that the deception would break Nina's heart.

On November 16, 2018, Ava decided to take steps to break up Kiki and Griffin. Ava drugged a bowl of soup that Sasha had ordered with room service, slipped into Sasha's hotel room, stripped an unconscious Sasha, and then lured Griffin to the room. When Griffin arrived, Ava knocked him out then stripped him and put him in bed with Sasha. Next, Ava arranged for Kiki to find Sasha and Griffin in bed together. The plan backfired because it was clear to Kiki that Griffin had been injured and Sasha had been drugged.

Two weeks later, Kiki Jerome was brutally slain by a serial killer. Shortly after the funeral, Sasha decided to return to Chappaqua, but she continued to return for visits because she had grown close to Nina and to Charlotte Cassadine. By March 2019, Sasha had been persuaded to extend her stay indefinitely and take an entry level job at Crimson.

Sasha remained uneasy about her deception, but she recognized that Nina would need to hear the truth from Valentin. On March 8, 2019, Nina played matchmaker by introducing Sasha to Michael Corinthos III. Sasha and the young business tycoon immediately hit it off.