Is it sufficient to give the stolen money in charity on behalf of its owner, given that the thief has repented but cannot return it to her due to his travel, and is there a solution for a debt whose owner cannot be reached?

The stolen item must be returned to its owner, unless the owner pardons their right. The obligation to deliver what is rightfully due does not cease due to distance. Giving rights as charity on behalf of their owners is permissible only when it is impossible to reach them. However, if it is possible to reach them, giving it as charity on their behalf is not sufficient; rather, it must be delivered to them unless they forgive and pardon. The same applies to debts, and the smallness of the debt has no bearing on the ruling.