Vaguely remember that UMass co-ed bathrooms.
How come your sister’s roommate’s shoes made the diff?
So essentially many people today are comfortable with the coed restroom idea, having already been implemented in some Universities. I’m sure the dons of yesteryear would agree /s.
So they'd think it was her roomie in the stall.
If you view it in the context of an 18-year old girl who'd been raised in those halcyon days when modesty was actually considered a virtue, it might make more sense.
She was just making a joke to illustrate her discomfort; I guess (not for the first time) I failed to make myself clear.