It's viewed that that person gives up such rights to safety and government concerns when they commit crimes. Of course, people who commit non-violent crimes and pettier crimes are placed in prisons with less security than those who commit more serious crimes like murder and rape because they're seen as less dangerous.
Oh, btw, C. City, this is actually what refutes that statistic you brought up as an argument. Because, while men are more likely to commit more violent crimes, what statistic means is that the amount of men in max security prisons for crimes like murder and rape are higher than the number of women in the same category. And while this does mean there is a correlation between how violent the crimes committed are with ***, correlation doesn't equal causation.
Secondly, the transsexual woman committed assault. That means she's gonna be placed in prisons with people who committed crimes of equal or similar violence or stature. That's why even if you have murderers and rapists in the same prison as a thief or someone who committed fraud, they are separated based on how serious the crime they committed were. So no, she actually still doesn't pose a threat to the women around her that wasn't there before because she'd be around women who committed a crime on her level.
What is the role of a woman becomes the question then. Is it the ability to give birth? If so, then infertile women aren't really women. And how would this come into play in a jail environment? It's not like women in jail need to or even want to be giving birth anytime soon, that characteristic being brought up in a conversation about should this transsexual female go to a female prison is irrelevant. Same as having a Y chromosome as opposed to having two X chromosomes: It doesn't play any significant role in being a woman in prison.