Is the mother considered sinful for accepting a low price for the sale of her deceased father's house, knowing that she agreed to avoid problems, and is what she received her right that she can sell as she wishes?

If the agent was grossly negligent in selling the heirs' house, the principal has the option to annul the contract if the sold item remains, or to reclaim its value if it has been disposed of. Gross negligence is that which is generally intolerable, and some define its limit as one-third or more. However, if the negligence was not gross, they do not have the right to annul the contract. It is not permissible for the woman to provoke the buyer into paying extra money.