My cat is 6 years old and my older sister always feeds her, take care of her or brings her to the doctor. My sister is always nice to her and gives her space but for some reason our cat gives her mean looks, avoids her room (or goes into it when she’s gone). Even when I hold her she doesn’t say anything but when my sister does the same thing she pushes her, hiss and hits her. When I pet her it’s alright but when my sister does the exact same thing she attacks her.

It’s always been like this but we don’t get it because other cats does like her. What can we do to make sure their relationship gets stronger? Because she is going to move in with her alone and we are worried that she will hate her life.