The same thing I said to my mum not so long ago. She won't listen and she gets upset whenever I mention anything to do with money.
Then she needs to stop burying her head in the sand and make a change. I know this sounds harsh but she is actively avoiding the problem and making sure people like you don't bring it up by getting upset.
Why not have a look for other places for her just now. Get some properties together (costs I mean not "you and her" together) and present them to her with the monthly outlay for each versus her current outlay.