Is it permissible for a needy woman or a needy brother to take something from the vow dedicated to purifying adjudicated wealth?

Fulfilling a vow (nadhr) is a religious obligation, and Allah Almighty has praised those who fulfill them. If no specific person or entity is designated for the vow, it should be given to any poor person or indigent, with relatives having priority, especially a brother. It is not permissible to give it to your mother to fulfill your obligations towards her, such as maintenance. If your intention by "purifying wealth" is to cleanse it from doubt by fulfilling the vow, this does not permit what Allah has forbidden.