1. Since the property was the self acquired property of Mrs. Banu, she was within her legal rights to have executed WILL in favour of her two sons A & B only and not giving anything to her daughter 'C'.
2. The daughter of Mrs. Banu can challenge the execution of WILL that it was done under duress, threatening, etc.. and claim for her share.
3. If the daughter of Mrs. Banu initiates legal action, naturally the buyers of land from A and B also have to fight.