Is it permissible to give one's mother a sum of money that was vowed as charity upon the fulfillment of a specific supplication?

Charity given to relatives is better than that given to others, due to the Prophet, peace and blessings be upon him, saying: "Charity given to a poor person is charity, and to a relative, it is charity and maintaining family ties." An absolute vow (nadhr mutlaq) must be spent on the poor and needy, and it is not permissible to spend it on others. If your mother is wealthy, it is not permissible for her to take from the vow's money. If she is poor, her maintenance is obligatory upon you, and it is not permissible to avoid paying for her maintenance by giving her the vow's money.