Husband death property and financial support denied to child & mother

My cousin had been living in US for last few years and she had returned along with 8 years old daughter after couple of years of marital discord and fighting.Child is US citizen.They were living in India without any support from the husband and divorce was not filed.My cousin husband passed away last month and now we realise that all properties earned by him has been transferred to his mother and/or purchased in her name.Also insurance money has been taken by her.Money earned by my cousin and kept in joint account has also been taken by her husband and given to his mother.They are not willing to give any share to the daughter.We are trying to find legal recourse to get the due share.Pls advise what and how things have to be done.