Dd1 is 13, oldest of 3 girls. She has always been a happy, well-behaved child and generally a pleasure to have around. She is quite quiet and shy and very much a 'closed book' so it's difficult to work out what's bothering her.
Sometimes I hear her crying in her room or the bathroom 
More often than not she won't tell me what's wrong and it tends to pass over. I know hormones can you make you feel crap so it could be down to those maybe.
She is a keen ballet dancer and takes it very seriously. I'm guessing but I suspect she's not as good as she'd like to be to consider professional training. To my untrained eye she is quite good but because of her shyness she lacks the performance quality of some of her peers. However she and I both assumed she didn't have plans to do it professionally but to enjoy her dancing as much as possible.
With regard to school and friends etc, she attends a girls school where she's doing very well. She has a few close friends and I think she would like more but she finds it hard to strike up conversations and she's also very choosy about people. She's now got it into her head that people don't like her (I posted below about this).
Tonight she asked me if she could wear a minimiser bra. Large-ish boobs do run in our family and she does seem to getting the boob gene, but having said that hers aren't massive yet, but maybe a bit bigger than some of her friends. When she started wearing bras a few years ago, she was very shy about the whole thing and refused to be measured in the shop. We managed after a fashion by me taking different sizes for her to try and me checking how they fitted (as best I could). I know from MN about the bra intervention thing and how we're all wearing the wrong sizes. The last set of bras I bought her were a 30D and I THINK this is the right size. She has just been on a ballet residential summer school and she told me most of the girls there were flatter chested than her. We had a discussion that lots of girls and women aren't satisfied with their boobs and it's common to want something you haven't got but at the end of the day you have to accept what nature gave you.
So I'm thinking from all this that she is unhappy with her relationships and her body . Or am I reading too much into it? I know it's really important to keep talking to your teen but sometimes I feel like a rubbish mum who doesn't ask the right questions.