Karen White attacked two women in 2017 while on remand at HMP New Hall, in Wakefield, for other offences.
White, 52, who is transitioning, was described as a “predator” who was a danger to women and children.
The court heard White, who was born male and now identifies as a woman, used her “transgender persona” to put herself in contact with vulnerable women.
Passing sentence, Judge Christopher Batty said: “You are a predator and highly manipulative and in my view you are a danger.
“You represent a significant risk of serious harm to children, to women and to the general public.”
She must serve a minimum of nine-and-a-half years for rape, sexual assault and wounding.