I was an ex-student, but as I said in my post, I am there regularly. I was there last week.
Cottrell has no mixed gender toilets, there are mens and womens. The INTO building near Cottrell has mixed gender toilets, those are floor to ceiling, fully self enclosed with sink etc toilets that open onto a hallway, you would not be walking into multiple people, they are single occupancy.
There are no toilets in Cottrell, where you will be walking into men using urinals apart from the men's toilets. This may be why her daughter was being laughed at, as she is likely to have been in the men's if this happened.
Pathfoot has separate toilets for men and women. The mixed gender ones, I have not been into, but I would assume they would follow the rest of the buildings, which are floor to ceiling indivudial cubicals opening onto the hallway. They may not be, but then there is the option of using the single sex ones, but I cannot guarentee that as, as I have said, have not used them but female ones exist.
The library in the atrium which is where all the shops etc are have female and male seperate toilet options.
I know someone is going to be like, anyone can lie about visiting etc, I don't have any from my visit last week, but I have a picture, mid August, dated in my photo reel, as I was trying to remember where I need to go back to, this is in the Cottrell building.