My sister daughter hates me ?

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 yseterday both my sisters was asleep and 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 and 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 she stop crying and 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 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 2 week old baby boy