Context: me (M16) and my sister (F17) are both track runners and we both run for the same team. This was in the car while my mom (F48) was picking us up.

So my sister was telling us about her day and the time she ran (not relevant), and basically complaining that she was off her game and that coach may drop her from varsity if she doesn't do better. Now I don't know what's a good or bad time for women, (which might make me TA), so I asked her "but isn't that a good time for girls?" and my sister kind of blew up at me. Saying I was so mysogenistic, same with my mom also getting a bit miffed. So I tried to do the right thing and asked what I should say next time. My sister yelled "Idk, just not that. Actually, maybe say something like 'isn't that good for you'?".

So I was conflicted. I asked some other girls on the team what I should've said and they all agreed there was nothing wrong with "for girls/for women", and that they didn't understand why my sister and mom had gotten offended. As far as my little research project yielded, "for girls" is the accepted terminology in the sport. Now here is where I may be TA again. Last night, I told my sister after we had gotten home that while I was apologetic for upsetting her, not only was "for girls" the accepted terminology, but also that I wasn't happy with her for not even giving me the benefit of the doubt that maybe I just didn't know that it was an offensive thing to say, considering it's pretty vanilla. (in my opinion).

Could some women weigh in here? I feel like there was nothing wrong with what I said but I could definitely be TA.

Thanks