Mary, if I may. After nearly 47 years in the gym, and like you a serious athlete and lifelong body builder, I'd like to address this. Forty years ago, this was very much the case, but, and kindly hear my proviso, depending on the gym, this is very much no longer the case now, although to be fair, it depends on the gym. If I head to a Gold's (assuming there are any left, that is) I fully expect to find jacked men, jacked women, bulked up physiques, plenty of chalk and barking and farts and all the screaming of HUGE reverberating against the walls. My home, man. However, far many more gyms have gone the way of Planet Fitness, although they are on their own planet if you'll pardon the pun, in that they specificially isolate those very people for public shaming. Talk about a business model. That said those are two extremes of the same bell curve. More likely, the weight room of the local rec center is far more gender and age friendly. You can I can specifically chose a hard core gym for performance, or we can find a shitton of gyms which are much more user friendly. All my 24 Hour (now defunct) gyms in Colorado had just as many women as men in the hard weights area. In fact, I've been in hundreds upon hundreds of gyms over the years, and I can't recall being in one where the kind of separation you describe is the norm. Maybe twenty years ago. I am not saying you're wrong; I am simply saying that if we're going to invite women to lift- which is what I also write about- I might be careful not to give the impression that all gyms are like this. They aren't, if for no other reason than you and I can find weight rooms in a whole lotta places that aren't popular with the 'roid types. Which is good news indeed. However, you point out what affects allus girls: the mansplainer. To that, the last guy who did that to me at PF was met with a discussion about the eight different ways ( I made that up) to do donkey kickbacks. Suffice it to say, said manly man placed tail between legs and skulked off. If you live hard like I live hard, we gotta know a lot about weights because, well, injuries. I do the same thing: I'm not in here for a pickup. I'm here to effing WORK. You don't get a 25 inch waist and my guns at 67 standing around running my mouth and primping in my Lycra.
BTW, my big bro wrote five books on climbs that he originated in the South Platte. Solid 5.11+ climber. Not my sport, but I sure respect it.