I don't think it's raavis job to ask for the kangans. First she found out the true story from Suman that mama was the one who asked to borrow them and then they kept it after the dad died. If anything Sumans brother is equally responsible for this and as Suman said she doesn't want to embarrass her brother and fracture the already fragile relationship. For shiva to ask is one thing fine but to use raavi as a bargaining chip is the wrong part. She and their relationship is now being used as a leverage between Shiva and maami and she has no right to say anything like she is some object for trade and raavi has a right to be hurt.