What can i do?! please help me?

this is my older sister's acount, and this is my problem: im 12, and everyone treats me like im a little kid. i know people are gonna say i wish i was young again! or youre gonna regret wanting to grow up so fast, but i wont. i would never go back when im older. some of my life has been the worst years of my life. i hate it soooo much! it drives me nuts! i cant wait until im 13, and people will stop asking me if i want a kiddie menu, and giving me the drinks with lids on them, because i havent spilled my drink at a restaraunt since 2nd grade. im quite mature for my age, but do you have any tips on how to be like...mature? i dont know. but my aunt is 32. and she considers me a little kid. please! im practically a teenager! i act like one.