What age do most girls start wearing make up?

i really wanna wear make up and i will be 13 next year, my mom says i dont need it, but i think differently. Some tips on how to convince her that i wont use a lot and im responsibly enough to know how much is enough would be great!! Im also an only girl and im right inbetween 2 boys. I told her i dont feel feminine and she just laughed. She was one out of 5 sisters so she wouldnt get it. She started wearing make up at 13. I dont think its fair cause shes the second oldest and my grams rules were you can wear make only if your responible. And my aunt( the oldest sister) started at 14, and my gram let my mom cause they did everything together, and i dont have that advantage. Please help and give tips!!!!!!!! Thanks!:D