My 13-year-old daughter has a training bra that she has been wearing 24/7 for almost 2 years now. When we first got it, it was her first bra and she has only tried on one bra when I got her fitted. I bought her lots of bras over the years but she will not wear them. She is struggling to get the bra on as her breasts are so much larger than the training bra is meant for. The last time I got her fitted she was a 34b cup, The training bra is meant for small busts let alone a 34b cup. I have no idea what to do.
It's entirely possible that she is uncomfortable with the changes in her body. Perhaps she would feel more confident in a sports or athletic bra? It may "hold her in place" more securly and allow her to run and play without drawing the attention of boys her age.
In the end, she has to wear the bra and feel comfortable in it, so you should get her input / feedback. Don't just go shopping for bras on your own, but take her with you. While you can also suggest bras for her, let her choose some herself. Grant her freedom in choosing ones she likes. You can then sort out some bad choices and let her try on the rest.
This has the following benefits
- You keep control (e. g. if she chooses too expensive or really inappropriate ones (like too sexy ones))
- You learn more about what she wants / needs, even without her having to say a single word, just by letting her explore freely and see what she presents you
- If she really refuses to, it's a good starting point for a discussion (listen to her, let her explain)
While you shouldn't allow really inappropriate ones, still respect her choices as long as they are still sensible and an improvement (she has to wear it, not you). She may feel insecure, as this is a crucial step in her development, so you could make it easier for her by
- Having someone else go shopping with her, whom you both trust (e. g. an older sister), but be sure she also trusts them and they have a good relationship
- Maybe not just go shopping for bras exclusively, but also for other useful itmes (so it's just mother and daughter going shopping, not the huge bra shopping event)
You could also get her input without going shopping, by asking her about it (like above, a trustworthy third party is also a possibility). The purpose should be to find out what she wants, so it should be comfortable for her and not, for example, be accusatory ("I bought you all those bras, but you...!").
After all, you don't know why she acts that way yet, and if she is anxious or insecure, for example fearing teasing, pressure would rather make it worse. She should feel comfortable opening up to you and not get punished for doing so. Make it a win-win situation for you both, so no negative consequences - it's about solving the issue, i. e. her getting an appropriate bra you both can agree with.