Without a bit more information, like when she does it (where are you and what are you doing at the time, what time is it in relation to feeding, are there other animals, has anything else at all changed - even your aftershave, or litter box placement) it's kind of hard to guess! Try to give some hints please.
Well the cat with no reason when i pass by her snaps at me or trys to scratch me or hisses at me.There has been no changes in us or in anything this just started ever since she was sterilized.There are other cats of course,her kittens
How recent was her spaying? And if she also behaves that way towards the other cats it could be because she wants the kids (kittens) out of the house, you may just be getting caught in the crossfire if she aggravated already.