A person's transition can be finished without surgery to change genitalia. She had a right to be there. Period. She wasn't waving her genitals around, and besides of which, German sauna culture is usually mixed sex anyway. I've spent tons of time German saunas and similar facilities, and it is highly unusual to segregate by sex in the first place.

This is raw transphobia.

And it's disgusting that you support it.