See if the property is in name of the mother then she cannot claim right even if you go for litigation then it would be waste of money as money factors work as:
1. Any property in name of hindu women is her sole property and treated as self acquired property.
2. Father purchased it from his income not from ancestral sources so it was his intent to give mother that property not to create a joint property of legal heirs. Further no legal heir has any claim on the property self acquired by father he can dispose at his wish.
3. Further today it stands in mothers name no matter mother has no income but she has valid title of property and she can transfer it on her wish.