The Prophet ﷺ said, "A woman is not to be married while her Amtah is still married to the same man, nor while her maternal aunt is."
حدثنا يحيى عن هشام عن محمد
عن النبي ﷺ قال لا تنكح المرأة على عمتها ولا على خالتها
Its isnad is sahih, and Muhammad is Ibn Sirin, mentioned previously at 577, 4349.