I live with my husband’s family who are neither upon the correct manhaj, neither do they have good manners. They spend their free time in gheebah and the like even in Ramadan. Is it permissible for me to complain to my husband about their condition when I am fasting?
Yes, you will have to tell your husband and complain to him about them because you will need to isolate yourself from them. This is not backbiting as they are doing this openly, and complaining about someone for a purpose is not backbiting.