Help on dying hair blonde?

so i want to dye my hair blonde like kristen stewart's hair here: https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg7ymd3IEHGIBDRq76O4oEIWHDkFdfARfrIbSWZN-Lyzf0jRlLcL_1pUa6c_PdviGVNpi0-rxUbbDP7OK6_8Gvbe5_NLVJhUVnNZqmbFN3AyqqGX_S0kXfReK89Z4yPoyF26naslyAB4CV6/s1600/Kristen+Stewart+Blonde+Hair.jpg but i know it's going to take a while to get my hair like this because my hair is dark blonde/light brown so i need to know how i can gradually get this kind of blonde hair?????? by the i don't want to wait TOO long, i'm very impatient :P also i think my moms gonna be pissed at me because i dyed my hair a bunch of times so how long should i wait before my next dye? and also my mom doesn't want my hair blonde because of the roots. besides telling her about a root touch up kit, how can i convince her?!?