Is the mother obligated to return the gold to her daughter that the daughter gave her to sell and spend on digging a well, knowing that the daughter refused to take it back then requested it after a period? And in the case of return, should it be in monetary value or gold, and should the value be according to the price of gold at the time of giving or at the current time?

Obeying one's parents is one of the most important matters in religion. Allah has coupled His right with their right, and the command to treat them with kindness with the prohibition of polytheism. The Sharia (definition) has warned against reminding someone of a favor, making it one of the greatest sins and a nullifier of charities. As for the money gifted to the mother, it is not permissible for the giver to revoke a gift after the recipient has taken possession of it, except in a few rare cases. Therefore, the mother is not obliged to return anything to her daughter after acquiring the gold.