Honestly, as a prisoner officer in the women's estate, your dd should have heard about Barbie Kardashian. This is basic.
Risk assessments are not worth the paper they're written on if they don't acknowledge that men are men.
And if you think male prisoners don't pose a threat to your daughter because they say they are women, you are in the land of la la.
Ask your daughter whether she'd rather restrain a man or a woman. Women bite more, pull hair more and can be utterly vicious. Men will break your bones. I know which I'd choose. If your daughter says otherwise, I'd be wondering about her honesty.
Properly supervised, no prisoner should be a danger to others.
This is utter (and by utter, I mean complete and utter) bollocks btw. You clearly have zero idea of what you are talking about.
If your daughter has told you this, well ... She is either ridiculously naive and should leave her job or is lying to you.