Is it permissible for a mother to bequeath most of her property to her daughter, to the exclusion of her son whom she describes as foolish, justifying this by her fear for her money due to his mismanagement, and out of concern for her daughter who is less fortunate in wealth and life?

You may not bequeath anything from your wealth to your daughter, for this is a forbidden bequest unless all adult, sane heirs permit it, due to the saying of the Prophet, peace and blessings be upon him: "Indeed, Allah has given every rightful person his right, so there is no bequest for an heir," and his saying: "A bequest to an heir is not permissible unless the heirs wish it." However, you may gift her from your wealth whatever you wish during your lifetime, provided that you gift your son the same, unless her need necessitates preferring her over him.