How could i convice my mom to lwt mw shave my legs?

Hi i am 13 years old and i am mad at my mom bcauz she dosent let me shave my legs nd she does not understand me nd i it emberrising 2 wear shorts nd 2 change into shorts in school nd have hairy legs idk how to make my mom understand me nd i dnt want to shave my legs behind her back bcauze maybe she will notice nd i wouldnt like to hide it from my mom how could i make her understand nd convince her??? plz help me!!!(: