Trust your mum's judgement - believe me, i used to rebel about the things that my mum wanted me to wear and the things I actually went out in and looking back she was right all along! She's got your best interests in mind and don't try to grow up too quickly as in years to come you'll regret not listening to her advice.

explain to her that sometime you dont think that what she may wear is suitable for her age, but your supposed to grow and make mistakes and if you look too old in it you canalways assesories with young things like glitter bracelets or girly heart necklaces.

when ever that happens to me my mom always ends up right trust me . also make an "oh, ok" half dissapointed face and ask if you can still get something else.works a charm

Let it go, there will be other tops. (Find one you both like - compromise.) In the scheme of things it's not worth the time and effort of disagreeing over. Pretty soon I guess you'll be out at work and choosing your own stuff anyway. xx