So, it is always a difficult situation when I am watching my two daughters and one has to go potty. For me, a lot of factors weigh in on if I take them into the men's room with me or send them into the ladies room. The family restroom is ideal, but not always available.
For my dd5, I ask her which she prefers. More and more lately, she prefers to go in the ladies room solo. I will allow it normally if it is a small (one commode) or otherwise empty restroom, which also seems like it would be clean. Also, she is afraid of the auto-flushing toilets, so that has to be a consideration. My dd3 I will send into the restrooms that don't have doors, but rather a few walls to walk around, and only with her older sister. That way I can hear them and they can hear me. I am wary of some restrooms that have heavy doors, which neither of us could hear through, and are difficult to open for the girls.
Most of the time it is a conundrum though. Safety is definitely the most important factor.
What do you all do?