Marriage

My friend is married to a girl after death of his first wife. he has a son with his first wife and living together. he and his family members have already suffered with false allegation in the court after accidental death of his first wife, which was closed now. the relation between his first in-laws and him are good now. but after the second marriage of my friend his second wife threatened him many times in reference of death of his first wife. she blamed her mother in law and sister in laws that they beat her after ten days of her marriage. she also blamed her father in law that he stares her. she do whatsapps messages to family friend of her in laws in which she defame her in-laws a lot and talk about her share in property. after one month of marriage she went to her father's home. she returned after one and a half month with her husband to her in laws home. During this period she was pregnant for which her husband and his family members took care of her but she was not satisfied. after coming he she tried to hurt her step son and abused her husband a lot. and after two months from returning her father's home her parents and relatives came to her in-laws home and put false allegations on them and took her with each and every belongings to her, to their native place. Since then she is in her parents home. Its about 10 months. She gave birth to a girl child. Now they have sent a hand written notice by and advocate. Kindly tell me what can we do in this case. He don’t want her in his life again as she behaves like a psycho. She can anything in his home for which they are not mentally ready. Please suggest.