Sister-in-law causing family problems. What are my available options ?

Sit all family members together and discuss each other to sort our the differences why you people think that she is arrogant and disrespectful and what made her behave with you people like that. What exactly the problem between you people you ask directly to her in a normal way without fighting with her if you people think you are completely correct and fair with her. The solution is to speak to each other and solve the differences in a possible manner.

Better you both reside seperately. This only suitable solution. To think the worst, your brother's sister may file a false dowry harrasment case against all of you. You cannot change mentality of such people.

Does your brother gel along well with his wife ? If he does, then one way of solving the problem is to have a separate place of residence for them - if he also has problems with his wife and not just you, other alternatives has to be looked into

--- Advocate C V Srinivasa