I have never thought of measuring my thigh!
It's an odd subject, for many women naturally store fat or have a distinct amount of curve in this area. And again, some don't. No big deal. But I think there's this weird trend for gaps and thinness right now, and so many women are thinking they don't measure up, if you'll pardon the pun!
Mine are 20 inches at widest part. I am 5"4 and size 8-10. This is actually a bit lower than my crotch area, so there's this tiny little gap above it. It is not the gap you see in popular imagery, so I guess my hips are fairly narrow (34 inches).
I also think we get super conscious of this area of our bodies due to current fashion trends 0 super skinny, form fitting clothes. It draws our attention to these parts whether we like it or not, and I NEVER used to feel conscious of my things prior to the skinny pants trend. Now I notice them all the time, ans always wonder if they are proportionate, too wide, etc. It is sad :(
Thing is though, I actually kind of like the fatter curve of a woman's thing area. I have a fairly flat and boyish body apart from my thighs....so the contrast is nice to be honest. It's like our culture wants me to hate them, but I don't think I can.
Not sure if they rub together, but possibly not - as I would be sure, I suppose. I didn't think weight had much to do with this, but I'm not entirely sure..