Can daughter in law ask share in property of mother in law

We are 2 sons to my mother. Father was expired in 2010. Then my grandmother give one small land (AP govt assigned land) on the name of my father. My father written this land in the name of me and my younger brother. We both had given this to my mother saying we don’t have any rights on this property on 04-10-2008. Later on, In 2014 my mother sold that property for INR 10, 0000.0 for her own needs. In that ten amount I took 4Lakhs for buying a flat. Actual flat cost 28L). The rest of 6L is using by my mother for her own needs. As I took 4 Lakhs, I purchased a land Which is approved by TUDA and registered on my mother’s name. Now, my younger brother’s wife is torturing my mother for property share / she asking my mother to buy a land for her. My younger brother’s wife allegation is that my mother given all the money to me to by a flat. Please tell me, is she has any right to question my mother ?