According to Section 10 of the Hindu Succession Act, 1956, the property is distributed among all the heirs including the widow of the deceased person. If there are no other shares, the wife can acquire the whole property of her spouse including the beneficiaries. However, According to the Widow Remarriage Act of 1856: “All rights and interests which any widow may have in her deceased husband's property shall upon her remarriage cease; and the next heirs of her deceased husband, or other person entitled to the property on her death, shall there upon succeed to the same.”
This has been repealed by Bombay High Court and now if the widow remarries she is still Class- I heir and need not give up her right over the property.
1. Widow of Son shall NOT have any inherent right on ANY property that is solely Title-Owned by Mother-in-Law.
2. IF property stands in name of Mother-in-Law (and not in name of Son) THEN Mother-in-Law is legally entitled to Sell /Gift /Donate /Mortgage /WILL .... her own property to ANYBODY, without any reference to her Widow Daughter-in-Law.