"There can be little doubt that this transfer was destructive for Mary," wrote Sereny in Cries Unheard. Mary had to adjust from a mostly male atmosphere at Red Bank to a full women's facility at Styal. She was a rebellious prisoner and was frequently punished, but soon adapted: "What I had to do was, yes, continue to fight the system, but I had to graduate from being a prisoner to being a con, and that meant that rather than being open and angry, I had to be closed and crafty." She also decided to go "butch." When her mother heard this she said, "Jesus Christ, what next? You're a murderer and now you're a lesbian." A consultant child psychiatrist, who did weekly group therapy sessions at Styal, observed that "[Mary] went a long way toward persuading her world that she was masculine. She strutted... and making up as if she had stubble on her face," and "rolled up stockings in the shape of male genitals and pointed this out to me in class. I think she wore these all the time." She would later ask a doctor for a sex change, but was denied ("It was the idea of not being me," she said.)
After being transferred to a less secure facility in 1977, Mary escaped. She was picked up, along with a fellow escapee, by two young men. In her brief time out, Mary lost her virginity. The guy she slept with later sold his story to the tabloids, and claimed she escaped from jail so she could get pregnant. "As time went on, my nightmare was the press," said Mary. "I never could understand what they wanted from me." Mary was moved to a hostel a few months before her parole in 1980, and she met a married man who got her pregnant. "He said he was determined to show me I wasn't a lesbian," she said. "It was hard for me not to think of sex as dirty." When she found out she was with child, she had a moral crisis of sorts: "But if I think that almost the first thing I did after twelve years in prison for killing two babes was to kill the baby in me... " But Mary felt she had no choice.