As per Hindu Succession Act:
If the women has acquired any property from his Father or Mother, in that case the first right will be of the heirs of her father and not husband, in case of absence of his sons or daughters
If the ancestral property has been partitioned, has been acquired by WILL the status shall change to self Acquired.
The self acquired property can be given away by the owner in his/her life time to anyone as per sweet will.
You may show the property documents/mutation record to an able lawyer dealing in such/property/revenue/family/civil matters at your location and proceed under expert advice of your lawyer……………before entering into agreement to sell.