Yes, believe it or not, kids explore their sexuality from early on, it's normal.
And in regards to other comments here:
You need to do absolutely zero about this. It's her body and nobody has the right to suggest that she's doing something wrong. Because she doesn't. Please be open minded and supportive and don't shame her. reply
If I was filthy rich and super petty, I'd have all my underwear made customized to my body proportions. Idk how others live, but the smaller size is always uncomfortable and the bigger is always slipping where it doesn't belong, it's awful. And in this hot weather, uuuuugh.
