I Am Married To Hostile Inlaws.

When I got married to my hubby, his twin sister was very angry with him. She wanted him to marry her best friend. Since then anytime I visit my mother in-law in port Harcourt, she always makes my stay unbearable. I have birth last seven months and since then she didn't come to visit.

Now she came with my mother in-law yesterday with her ten years old child. I think she has poisoned the little girl's mind because the attitude she has been showing is unruly. She is arrogant, disrespectful and saucy. For example when she finished eating and I asked her to wash her plate, she said if I couldn't wash it I should leave it. 

Around past 11 yesterday she was still watching tv nd loudly for that matter. My babies were asleep so I had to tell her to put it off and go to bed but she gave me the shocker of my life as she told me that I didn't have the right to tell her to put off the tv as I was not her mother. Then again this afternoon, NEPA took the light as she was watching tv and then she walked...

into my room and said Mama Nathan wont you go and put on the generator. 

The worst part is that this girl is always so respectful and calm when my hubby and her Grand mum are around. I don't know what to do. I don't want a situation whereby if I complain the Grand mum might doubt and reason that it is not true.

Because i'm not in good terms with the mum and she is aware. Please,

 I need advice on what to do so I don't loose control one day and smack her.

Thanks