Why does my mom hate me and not my sister?

ok my mom acts like a real *****. my mom spends little or know time with me. she said she doesn't have time when half the day she is sitting down playing video games on her computer. and where a moderately pore family but she doesn't have any problem with that on my sister. i need a haircut. i haven't gotten one since december of last year. she said she cant afford one for me when she spent $150 just on my sister to get Highlights Brade's and her hair died. she pays 230 dollars for my sisters cheer leading teem. she never does anything with me alone and she goes to beaches she eats out and dose all of this **** with my sister. and my sister curses. she said s**t f**c ... anything she wants and she doesn't care but when i shay sut up to my sister she grounds me. is she a feminist or something