Her brother is going to marry a corrupt girl and his family want to deprive him of his inheritance

No File Exists
Check below answers in case you are looking for other related questions:
It is not permitted to deny a Muslim child his or her inheritance
Division of the estate of one who leaves a wife, two sons and a daughter behind

No File Exists
Related Answers:
His father and paternal uncle died, then his grandmother died. Does he inherit from her?
She died and left behind a husband, two daughters, two sisters, a grandmother, a maternal uncle and two maternal aunts
Does stealing prevent a person from inheriting?
It is not permitted to deny a Muslim child his or her inheritance
Division of the estate of one who leaves a wife, two sons and a daughter behind

Recommended answers for you:
Du’aa’ of the fasting person when breaking his fast
Divorce (talaaq) in the state of anger; and is it necessary to have witnesses to divorce?
Ruling on buying and selling shares
What is the ruling on drinking one’s wife’s milk?
Adhkar Recited After Prayer