I have ask this alot but i am trying to fing out y my sisters baby girl hates me pelase help?

So I have 2 sisters a twin and our other sister well my sister just. Hurt her back so me and my twin are helping out. With her 11 mouth old baby she hates me. Ok so yesterday both my sisters was asleep. The baby was awake in her crib so I thought. I would get her out and give her something to eat and give her her bath. I went to get her out and she smacked my hand. And said "NO" and was screaming for her mommy. So when her mommy came in the room she stop crying. She loves my twin aways have one day both my sisters was out. So I watch her baby and she was standing in her crib so I though. I would get her out so I went to get her. Out the crib and she smacked my hand and said. "NO" and cryed for her mommy and I told mer mommy is out an she cryed for my twin and I told her she was not here either so I picked her up any ways and she went mad smacking me and crying for mommy Y Does she hate me please help PS I have a baby boy 2 weeks old that she don't like either she hits him and I tell her not but I love her she even bites him but her momtells her no to but she don't listin