My Sister in law is not willing to stay with my brother

Hi - My brother was married in Feb 2015.Till 18 months both husband and wife were getting alone well. Since last Sep 2016, she went to her place for studies & now unwilling to return back. She is being supported by her mother and father. We have visited her place several times requesting her to come back but she is not ready to do so. She says she is not in good terms with her husband and she wants to pursue her career goal by staying with her parents. We did a meeting with all elders one day. In that meeting also she said she is unwilling to stay with my brother. Due to this tensions rose & she, her mother & my wife had a heated argument. After this she was admitted to hospital due to fever. When my brother and mother visited her, both were blamed by her mother that she is admitted to hospital due to mental harassment given to her which is not at all true. They are not ready to talk to us and I am sensing they may have approached a lawyer to put harassment case on us. How do we avoid this? Can you please suggest a legal solution to this issue?