How to convince my mom to let me shave my legs?

I'm Asian. I have black hair and I'm 12.I have thick hair so pretty hairy.Well that's because I asked my mom once when I was 11.She said no so I took one of her new disposable ones and shaved.. I did that for about 3-4 times then I stopped.. I'm already self-conscious enough.. Also have a low self-esteem cz I am a short person with hairy legs and a blue birthmark on my leg kinda makes it worse..But Im getting over tht..She wont let me shave, wax or use nair... She said nair can cause ingrown hair.. I'm starting to get pit hair?.. I already have some ingrown hair from when I shaved without her knowing though.... PLEASE HELP ME!!! I wouldnt even wear shorts/skirts or dresses anymore not even in summer...