Is it permissible for a mother to donate the clothes of her 26-year-old daughter without her consent or knowledge, knowing that the clothes were purchased with the daughter's own money or given to her by her parents?

This mother is wrong in what she is doing. She is not allowed to donate from her daughter's money without her permission and consent. The Hanbalis restrict the permissibility of acquiring ownership from the son's money to the father only, while the الجمهور (majority of scholars) hold the view that neither the father nor the mother are allowed to acquire ownership from the son's money. The mother must stop what she is doing and guarantee what she has taken, unless the daughter forgives her. We advise the daughter to forgive her, keen on her mother's satisfaction.