Why does my mum hates me but not my sisters.?

You need to wait til a time when the atmosphere is calm and speak to your mum about it, explain how you feel and tell her that you find it unfair, tell her how your working your off for your exams, and if it really is true then when your exam results come in you can prove to her that you have, then she has ought to beilive you:) hope this helps? :)