Ms Beale, 32, had always insisted that the baby, born in a hotel bath during a trip to New York in 1994, was still-born, and that she had panicked, wrapped its body in plastic bags and cleaned up the bathroom.
But before her trial, she was persuaded to plead guilty to manslaughter in exchange for being allowed to return immediately to Britain, where she would be treated by psychiatrists.
Speaking on Radio 4's Woman's Hour, Ms Beale, said it was a "terrifying" experience, but that she was now able to leave a relatively normal life.
Recalling the night of her arrest, she said: "They had me handcuffed to the bed. The detective guy took my clothes and everything. I thought, if I could keep myself together and tell them what had happened, then they'd just let me go home."
She said she had been motivated by an overpowering urge to bring the child's body back to England.
"He [the investigating detective] said to me `why didn't you leave her here and you could have gone back to England and no-one would have known?', but I just knew I had to bring her home.
"It all seems bizarre in retrospect, but I'm just a normal person," she said.
Ms Beale, a civil servant from Chingford, Essex, spent eight months in the notorious Riker's Island jail, sharing a cell with prostitutes and drug addicts.
The harsh regime of beatings and ill-treatment forced her to make a plea bargain, she said.
"I just remember it was kind of like - the state I was in I felt that whatever they said to me I'd say yes to because I wanted so much to go home."
Psychiatrists now argue that Beale was "in denial" throughout her pregnancy and in shock after the birth, and needed hospital treatment rather than imprisonment.
She said that being able to bury the baby, who she later named Oliva Ann, in Britain, made it easier to deal with her loss and enabled her to return to her job at the Department of Health.Reuse content