She is saying if a women prisoner is assessed as being a danger to other women then she is put in the male estate" Is this true?
I believe it can happen, but it's incredibly exceptional. And the reason it happens is because virtually no women are that dangerous, therefore women's prisons are not equipped with security levels (including staff) capable of dealing with someone posing that level of risk.
But I'm not sure why she's making that point. If women can be put in the male estate, then what's the objection to putting transwomen in there? If women's prisons can't handle dangerous females, they certainly can't handle dangerous males.