R.J.
If it's just me and my 6year old boy, I take him in the Ladies room.
If he's with friends...or if his dad, or a male friend is with me he goes into the mens with them. Because then, he either has an adult who cares for him looking out for him...or he has safety in numbers. Same token, if it's a single person restroom he can go by himself...like at a cafe. I DO go with him, to make sure the restroom is safe and clean though first.
My feeling is this: Who do I really care about? The health and well being of my son? Or a stranger's offended dignity? Hmmmm....not a hard choice. Especially when the offended diginity is a cultural construct. Ummmm....don't we all have son's, dad's, brothers, boyfriends, cousins, husbands? Do we refuse to use the same bathroom at home? It's not like he's peeking under the stalls...or being rude. So it's a culturally disapproved choice, but hey. So was women voting. Just because something is "culturally" the norm doesn't make it the right (or the smart!) thing to do.
Many bathrooms only have one entrance, but many others have TWO. So, while most people are good people, all it takes is one pervert or one kidnapper. Nope. Sorry. Huh-uh.
Ironically, MOST of the time, when I take my (very tall) 6 year old in...I either get a relieved glance from another mum (like the "oh, good, I'm not the ONLY other one who does this!" look), or a big grin from someone else, or somehow, right on our heels come another mum with an "older" little boy...and then after her another...and another.
In most situations it's the SMART thing to do.
In the 70's, my dad took us girls into the men's restroom until we were 9 or 10...we just had to "look the other way" as we were walking past the urinals. <Grinning> And if we didn't "behave" he threatened to have us "pee in the parking lot" or something else equally silly. A very silly man, my father. But very honorable. He felt that since he was the one who was responsible for us, he wasn't going to leave us to the 'kindness of strangers' to protect us if something happened. So then, he was worried about us getting hurt...and him not being there...and depending on a stranger to help us. Then again, he may have just not trusted us not to make a mess. Nowadays of course, we're concerned about strangers hurting our children...instead of being there to help.
As far as traveling in Europe, I have very very RARELY run across the "squatty-potty". They're very common in Asia (although they're usually porcelain...and if you look closely you'll even see names you'll recognize, like Kohler, on them :), but at least in Italy, Switzerland, Germany, France, the Netherlands, Norway & the UK...I've never seen them.
My experience in Europe is that it's MUCH safer (as a rule) then the US. In scandanavia you even find little flocks of baby strollers WITH BABIES!!! parked outside of shops...while the mums are inside. As with anything it depends on where you are.
EVERYWHERE in Europe though is about a zillion times more kid friendly/family friendly then anywhere I've lived in the states. I would expect ZERO problems with your husband taking your little girl to the loo with him.
:) R