What is the ruling on speaking about a maternal aunt who has greatly wronged the questioner, despite the questioner's kindness towards her, and how should she be dealt with, especially when visiting the home of the sister who is married to the aunt's son?

The maternal aunt (khaalah) is a blood relative whose ties must be maintained, and it is forbidden to sever them. Her mistreatment of you does not permit severing ties with her, nor does it negate her right to kinship ties, for the one who maintains ties is not the one who merely reciprocates. It is necessary to endure the maternal aunt's mistreatment, forgive her, and seek reward from Allah. For whoever maintains ties with ill-treating relatives, Allah will help him against them. As for speaking about her in her absence in a way she dislikes, that is forbidden backbiting (gheebah), unless she has wronged you, in which case it is permissible to mention your injustice, based on the words of Allah the Almighty: "Allah does not like the public mention of evil except by one who has been wronged."