I need someone’s advice???

So this is sort of a long story. My fiancés mom is religious and considers herself a catholic woman. She is currently in another country for stomach repair surgery. Sometimes she texts my fiancé, which is totally fine. She tells him she loves him and is sending blessings his way. She also texts my fiancés sister every single day. My fiancé and I both were talking to his sister one night and said that she receives a text message from their mom every single day. Here is where it gets interesting. The text message that my fiancés sister receives is a “Prayer” text message where their mom is prayer for my fiancés sister to send their mom money. She brought more than plenty of money to take with her on the trip to pay for her surgery, money, food and travel costs. Sometimes she texts my fiancé and says she needs money for non essential items like my fiancé received this one text from her before New Years saying that she needed money because she wanted a nice dress to wear on new years. My fiancé doesn’t have money laying around to blow. He has tons of bills to pay because he owns his own business. Another thing I would like to add is, remember how I said she considers herself religious? She has been living with a lady that practices witchcraft. To me, If I’m religious like that why would I want to hang around people like that? His mom is also notorious for stealing money that doesn’t belong to her. She one time broke into my fiancés money safe style he was still living with his parents at the time and when he asked what the money was for she said she needed it for Christmas gifts even thought she didn’t buy anyone gifts. My fiancés Dad has caught her sending money back to the sketchy people she lives with currently. Am I a bad person for not wanting to respond to her messages when she texts me? It honestly creeps me out some of the things I’ve heard people talk about her friends sketchy things she’s gotten into. I don’t want to associate with that. I remember when my fiancé and I first got together his mom asked to borrow $400 and I told her I couldn’t even afford my own rent. I feel like I can’t form a mother in law bond with her because of all the sketchy things she’s into and I really don’t know what to do about it.