What a better indication for upper body strength results among women

I was thinking about something for a while. When trying to gauge the strength differences between men and women. And noticing how they work out in the gym and various other places. I notice that men prefer using barbell and women prefer using dumbbells for gaining strength. Would anyone else agree or disagree with that with these observations?

　
Being able to do many reps at a lower weight level or doing less reps at a higher weight level. Example a friend of mine is about 135 lbs of solid muscle. She can do her body weight on bench press using a barbell for about 20-25 reps for 2 set. She can do a lot more weight on bench but her rep and set level goes down. Does that make her stronger or does that make her having more stamina?

Any other observation or comments in this subject are welcome.