1. since ur brother wont be happy without his daughter, FORCE him to be happy without parents. after all the parents are old and will die soon.
what about daughters happiness? look out for a solution where everyone is peaceful. one solution can be staying nearby to parents. you can still remain connected with parents even though you are physically away. Parents always want wellbeing of the children. your brother is also a parent. No one can predict death? we are all going to die one day.
2. if she is not happy with courtesy visits+sweets, go there and kneel down and fold ur hands. ask ur parents to also to do the same.
you are not going for begging. giving a courtesy visit/sweets can mean showing respect/concern towards daughter in-law. that will diffinately give assurance to her parents and also improve relation.
3. do not say a word if she takes things from her house (though she only visits “this house” like a guest or a boss) and helps her siblings and parents with this.
atleast not “chori”- if she had giving something to her parents or sibling living in a separate house can you dare to say Chori?. conflicts starts here..do you not give gifts or presents to your parents and siblings?do your parents & siblings give gifts to you? what is important is what was that she took (stole). is it a Jwellery of MIL/SIL? or some small houseold article?? whether it was when she was living with you or she was living in different house??
4, last but not the least, a man has all the duties and a women has all the rights.
men and women both have their respective duties and rights.? question is do they both follow religiously??