Why does my mom yell constantly and boss me around?

ok we have a great steady family. and my parents are together. shes not mental at all. but she yells all the time. she wont let me do anythin. so i accpet it. its summer and i use my comp and she yells at me. ive finished everything for summer work but she yells. she says am un lady like. and am clumsy. so i was walking and someone pushed me and my yogurt spilled. she called me a stupid child. she yells at me like 4 times in an hour. i try to avoid her adn then she says i dont love her. her parents didnt do this to her so its nto a family thing. thank goodness am more than a head taller than her. or if not when i was smaller she even slappd me :[ but hell no she ccatn do that naymore. i ate to argue but i love to prove a point and she says am bn disrespectful. whn i stop talking she gets mad..seh bosses me around. i can go up and down the stairs like 345696578 times in one day running errands. and when i sit to talk to a friend she says am lazy and un lady like :( i love my mom...at least i think so