Is it permissible to deprive the paternal aunt of her full legal share of the inheritance, and to be content with giving her only what suffices her to live with dignity, due to her ill-treatment of the parents and her not being in need of the money?

The paternal aunt must be given her full share of the inheritance without reduction or delay. Whether she mistreated the parents or not, her right to inheritance is established by kinship, not by piety or good character. The same applies to a disobedient sister. It is obligatory to fear Allah and give the paternal aunt her legal right. The Messenger of Allah, peace and blessings be upon him, warned against injustice and wrongfully consuming people's wealth. The paternal aunt's old age or her suffering from Alzheimer's does not justify depriving her of her share; rather, her share should be given to her guardian if she has Alzheimer's. If the heirs are the wife, daughters, and full sister, then the wife receives one-eighth, the daughters two-thirds, and the full sister receives the remainder by ta'sib (residuary heirship). The full sister's share would be five parts out of twenty-four, while the wife's share is three parts out of twenty-four.