When is a first bra a necessity?

First have a talk with her and tell her that every little girl becomes a woman and they ALL HAVE to wear bras. Make sure it's just the 2 of you so you don't embarrass her if that don't work then let her get made fun of a little bit, it will teach her. She is getting boobs and becoming a woman. Ask her if she wants to come with you to pick them out.