Should my sister take Khula or keep her marriage?

As-salam-allayakum, My sister got married a year back. My brother-in-law is asking her to take Khula, whereas we want to keep the marriage. Following are the issues in marriage; 1) My brother-in-law has Pre-mature ejaculation and erectyle dysfunction. He also have performance anxiety, He is in mid 40’s age. Rather than accepting this as problem and getting treated for it, he straightaway blamed my sister and now is asking that she takes khula as he is unable to enjoy sexual marriage life. My sister got checked by doctor and she doesn’t have any problem. 2) My brother-in-law family was pressuring our family to get their uneducated daughter married to my brother who is younger to their daughter, this was no match and there was no agreement between our two families before or on my sister marriage. They kept on pressurising us for almost 6 months and now my brother is married, they are saying that everything is over. 3) My sister is not treated very well and her husband doesn’t talk to her or support her. he also don’t support her financially, infact always eyes for her salary. She is living with us and has only stayed with her husband for 35-40 days in one full year. Whenever She wants to go to her husband house, she is questioned why she has come and he (my brother-in-law) tell her come only when he calls her (which he never does). Please give us fatwa, in this condition what should we do? As my sister want to keep marriage and my brother-in-law wants she should take khula. Also, what are the rights of my sister, if she takes khula, does she get backs her jewellery, salary etc? Allah Hafiz