Proposing to a righteous woman and intending to cut her off her bad family

Q 1: I got engaged to a Muslim woman who has a B.Sc. And was working on her Master's. Now she is staying home and is wearing Niqab (face veil) Al-hamdu lillah [All praise is due to Allah]. Although none can verify this but Allah, I regard her a good person In sha’a-Allah (if Allah wills). However, her family has a bad reputation. We learned from their neighbors, owners of the neighboring shops, and our relatives who live in the same area a lot of shameful things. For example, her mother had a very bad reputation in her youth and her other daughter follows in her footsteps. The father has no say at home and everything is controlled by her mother. Moreover, one of her brothers is a thief and was imprisoned several times, the other is an alcoholic and drug addict, while the third is licentious. The whole family does not offer Salah (Prayer) except for my fiancée. They use obscene language and abuse the religion of Islam. They are very rude. I hesitated to propose to her as the Messenger of Allah (peace be upon him) said, (Part No. 25; Page No. 384

A: If the matter is as you have described, there will be no blame on you to marry her in order to save her. You should advise her family using fair preaching. You have to visit them to enjoin the good and forbid the evil. However, if they do not respond, you should abandon them for fear of Fitnah (temptation) and to avoid evil.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.