Hunchback?

family, friends are all worried about my back posture. I dont know what they are talking about. I dont have bad back posture, or even worse, I am not hunchback, as my mother says. she calls me hunchback of notre dame whenever she sees me hunchback. and my mother told me that my aunt told her i dont stand straight. family members, sometimes even friends, tell me that. wut shud i do? maybe I dont have good back posture b/c now Im growing older (girl) and I dont want to stick out my _____ (you know what!). but i lack confidence on what a girl grows and I dont wanna show it. im scared. so i dont know what to do. help!