10 year old developing body


My Daughter is 10 and her body is changing at an accelerating pace. She’s been getting body odour and wearing deodorant since she was about 7, she has hair under her arms and has become much broader all over since April, not to mention the mood swings! She has now started developing breasts which is the part where I need some advice! She will happily talk about periods with me and her dad and isn’t shy is the slightest in that area because she says she’s learned about them at school. But at the very mention of boobs and bras she will clam up and refuse to talk about them. This has been going on for about 6 months or more, way before her body started changing. I think someone in her class made fun of her friend who wore a bra even though she didn’t have anything to put in one, so maybe that has something to do with it. I’ve bought her some little bras in M&S but she won’t even look at them, let alone try one on. She’s been wearing crop tops for years but now even has an aversion to those and is refusing to wear one when she goes back to school next week. She gets so worked up and stroppy about it and ends up arguing with me. I’m anxious for her as they have to get changed for PE together (boys and girls) in the same classroom. She needs to wear something under her school blouse! Can anyone offer any advice to talk her around??