Does my not speaking to my abusive aunt, who has greatly wronged us and slandered my honor, fall under the forbidden severing of kinship ties in Islamic law?

The Sharia (definition) commanded maintaining kinship ties and forbade severing them, even with those who sever them. The obligation to maintain kinship ties is not waived by a relative's ill-treatment or harm. Therefore, it is not permissible to cut ties with the paternal aunt; rather, it is obligatory to maintain ties with her in a way that does not cause harm to the one maintaining them. Kinship ties are not limited to visitation only; they are achieved through visitation, phone calls, correspondence, greetings, and anything that is customarily considered a connection.