Responding to the replies about my above post/experience yesterday (sorry -rushing out so can't return to the thread until later) -
The man did look uncomfortable with me and/or DD being in the same fitting room. However, he was getting the benefit of the mixed sex environment by having his wife there to assist him. I thought it would have been hypocritical for him to moan about it. He wasn't to know really if it was me or DD getting dressed in the cubicle a few doors down from him.
Neither me or DD felt we were at risk. The doors were lockable and it was a public space. If he happened to be a predator and wanted to attack us at that moment, he would have had to kick the door in with some amount of force which would have attracted attention from staff. For us, we didn't feel vulnerable. My DD knew to lock the door behind me every time I left to get her different sizes etc. If I didn't think she was capable of doing that, I wouldn't have left her alone at any point. However, she's old enough to know to do this.
Yesterday, I only saw good sides of the mixed sex fitting rooms.
The man - he got to have his wife there to assist him.
Me and DD - we didn't need to spend time looking for the 'correct' changing room; this one was right next to the kids' section (between the kids' section and men's) so was easy to go get different sizes etc.
The man did look uncomfortable but I'm not sure why. It could have been any number of reasons. Maybe he just felt self-conscious talking about his size, what fit and what didn't in earshot of strangers? Without asking him, we'll not know. If it was because he was in a separate locked cubicle from my DD (who was also in a locked cubicle) in a public space, I would be interested in hearing why. In my opinion, it was less risky for them both than them being out on the shop floor side by side in the queue, for example.
In terms of lingerie, I would feel uncomfortable (as would DD) talking about my breasts in earshot of men. DD would feel mortified discussing this in front of anyone regardless of sex! I would prefer there to be a single room with a lockable door with no gaps to prevent people from hearing our conversation. It would be more for embarrassment sake than safety, though.