Is it permissible for a woman to write a will bequeathing all her wealth without considering the legal heirs, whether she is single or married and has no children?

A will of all one's wealth is not valid for someone who has an heir, except within the limit of one-third. A bequest to an heir is not permissible unless the other heirs approve it. Causing harm through a will is forbidden, such as bequeathing more than one-third or making a bequest to one heir with the intention of depriving others, because Allah Himself undertook the division of inheritances.