pls I need advice

What does it mean when all you ever did was help your sister who is a single mom and all she doesn't is belittle you and tell your other family members that you're a bad person and bad aunty and I should watch her child For free if I was a good sister ? I don't get it I have been caring for her daughter for 3 years and she will Alwyas have this hate towards me for no reason cos we don't get along