GUWonder

There are perceived girls of ~6 years of age who do the same, in the women's restroom and/or in the men's restroom. And there are perceived same-sex (at-birth or otherwise) (as at the sign at the restroom entrance) adults who do peek into the stalls at time.

Also, given that men's restrooms tend to have less private urination areas than females' restrooms, what are men traveling by themselves with c 6 year old girls to do? Not all of the kids can wait by themselves alone out of sight of their adult caretaker in an unfamiliar location.

The solution to some of this is to try to use restrooms marked for family use and/or that are meant for wheelchair users too. But even that isn't always a functional solution for the circumstances. And even that isn't considered ideal by some. Short of having another party being sufficiently trusted for taking the responsibility of at least temporarily watching the child, these situations do have their challenges. And yet it goes fine most always, even with these situations of a parent traveling alone with a young child of the opposite sex as the parent on the trip.

If peeking into the stalls is possible when the door is shut, then the restroom users don't have absolute privacy -- and that relative lack of privacy seems to be by design (whether to save money or to limit "mis-use" of the restrooms). There is no absolute privacy against peeking into restroom stalls in a multi-user public restroom area with lots of traffic when the stalls used were designed as such that peeking in is possible -- whether done by boys or girls, whether done in the women's restroom or in the men's restroom.

Men or women wanting privacy from peeking boys or girls or others in airport restrooms should perhaps look at options beside those of using restrooms that were designed so as to allow peeking. The family/wheel-chair-user restrooms are one such possibility at many airports, FRA included. Also, airline/airport lounges for premium airline customers or those with lounge memberships of sort may have a few additional choices for restroom/bathroom use; and airside/transit/airport hotels too. But the bigger issue may be bathroom use on the planes than on the ground.

As someone who frequently took flight trips as a child with just one adult caretaker of the same or opposite perceived sex of myself, I thought things worked out fine and better at airports than even at (non-airport) shopping malls. And things have only gotten easier for adults in this situation as time flies forward.

She should indeed do what makes her most comfortable, for the alternative to that probably isn't a good idea.

i would suggest that if a child this young is going to wait outside by themselves (or otherwise may be separated) then having them have the adult's roaming cell phone number or other means to call/contact the adult in real-time may be a good idea. This could mean writing down the phone number on something on the child, having the child have a cell phone during the potential separation times on the ground,, using wireless data for partial live communication channel while one is in the bathroom and the other outside.

A few days ago I saw a sub-7 year old child separated from his mother due to the metro train doors closing in Copenhagen such that the mother ended up on the train with me and the son missed the train because the son unexpectedly got blocked from boarding by someone rushing off the train at the last second. Doing that which is most comfortable for someone else resulted in that issue.