She probably loves the way her hair feels! I wouldn't worry, though. I'm sure she will grow out of it. I had a horrible jerking tic when I was younger that my mom obsessed about, but I grew out of it.
I think you're doing a great job trying to keep her hands out of it! Maybe someone will have some more practical advice that I don't have, but I just wanted to give you some encouragement. She's so young and she will go through so many different phases.
I'm a 3b, with 3c underneath.
Used to be CG, now I'm not. Using Suave Aloe & Waterlily shampoo & condish, JoiWhip, BRHG, Suave Aloe gel, Aussie Tizz No Frizz, and anything else that looks good!