I was curious to know what would be good suggestions in this situation.

This is in Kathmandu. You have a big family with several sisters and a brother, most of whom are married. your older brother marries a woman and she starts to behave selfishly, disrespectful towards your sisters and your parents, even making your mom work while she is out shopping or to her माइत (she does not work like in terms of earning money). Basically your brother marries that woman based on her looks, because she has no education, not from like established family, etc. She exerts her force on your brother and other family members while being a new family member, and due to her behavior your sisters do not like to come to the house where your parents live, so they visit only on special occasions. You feel bad, yet being a younger member of the family you are respectful to your sister-in-law, but inwardly there is that feeling of complex emotion within. You don't want situation to go bad as you love your brother and everyone in the family. You don't live in the family because you are overseas, but you want to go back to Nepal.

I was curious what you would do in this situation.