Long background to avoid dripfeeding:
DD is just recently 12, and went up to high school this year. At primary she had packed lunches, and for the first couple of months at high school the first years are kept to the school premises at lunchtime. We've been giving her money to put on her lunch card, and she says she's been having pasta, pizza, burgers etc (menu sounds healthier than primary if not what I would consider ideal). They're now allowed out of the school at lunch, some people go to the chip shop, some to Asda, DD said she would stay at school. She has her lunch money, and we've also recently moved from weekly pocket money in cash to a monthly amount by bank transfer to get her used to budgeting.
Home food is not the healthiest but not awful, they get access to biscuits etc. we're careful about sweets as DD has a brace and has had issues with bands coming off, difficulty keeping it clean etc.
She's at a friend's just now, and I've gone into her schoolbag to get her water bottle which has been in there since Friday and needs washed (I know, boundary/privacy vs not letting it fester). I also found a biggish chocolate bar wrapper, quite a few Maom wrappers and an empty packet of chocolate digestives.
I feel I want to ask her when she bought them, was she sharing them, how long did it take to get through them etc. I need to know if she's keeping food in her bag as we live in a tenement flat and have seen mice recently, so are fussy about food being in boxes etc. I don't mind her having biscuits etc, she has a lot of walking to school and round the school campus, but I don't want her eating loads of it and she does need to be careful with her teeth/brace.
Any tips for raising this with a sensitive preteen prone to tears/flouncing (no periods yet but seeing definite hormonal type behaviour, and she is very likely to fly off the handle)? I don't want her feeling she has to hide food, or tell us everything she does, I just want to equip her to make sensible choices.
Sorry for length - I don't really seem to be able to manage brevity!