Re: Siblings
I think ur sister has low self-esteem due to the emotioanal violence her husband has inflicted on her, and does not know anything else. This may be the reason that she planned ur marriages - perhaps this is what she has been taught to believe. On the other hand, it may be that the only place where she has control or power is when she is dominating u and ur family.
Ur sister need help and preferable to get out of the marriage. Otherwise ur niece will be emotionally affected by it all. Seeing such behaviour from her father on a daily basis will lead her think such behaviour is normal - this is how she will be conditioned to respond to situations. U need to show her that such behaviour is wrong.