First, let me start by saying, please no statements about "Why don't you put her in a home?". For reasons I will not discuss here, that is not practical or possible at this time.
My wife is her (nearly) 88 y.o. mother's legal guardian. Until recently, she was also her financial conservator. However, despite the fact that the court acknowledged the fact that there had been "no evidence of any malfeasance" on my wife's behalf, the judge decided to reassign the conservatorship in a futile attempt to stop my mother-in-law from complaining about how her finances are being managed (in fact, she is complaining because she, herself, does not have unlimited access to her money and assets). According to the GDS, she is about stage 4.
My MIL lives with us, in a home that my wife purchased for her mother with permission form the court (using her mother's finances) in order to preserve her mother's assets (it cost about $4k-$5K per month to keep her in an assisted living facility, vs. under $1k per month to pay the mortgage, plus my wife and I do the maintenance and grounds-keeping here and pay rent - into the conservator account - nearly equal to half the mortgage). She has fantasies and delusions of "going home", back to either the town she grew up in or to the town where she lived with her late husband. She is also prone to paranoia.
We have been trying to do things to help her settle in and settle down including getting her to participate in things like gardening (my MIL was formerly a Master Gardener) or going to the senior center. We even found a way to get her to a church she likes.
Problem is, whenever my MIL is upset, she calls up various friends and family and complains to them. She often, whether intentionally in order to get sympathy, or simply due to the dementia, will lie to the people she calls about how things are for her here, or twist things that are said to her (for example, she tries to insist that this house is for sale and demands that my wife and I "buy it from her" and "send her back home", and I tried to tell her that since she has a conservator, she does not have the legal authority to sell the house. She twisted that into me telling her that she "has no rights here" - which is NOT what I said at all!).
She has had a friend for many years, who she especially likes to call and complain to. This friend has been apprised of my MIL's mental state by several different people, but she seems to be in complete denial over it. She also gives my MIL some very bad advice, including telling her not to trust my wife or cooperate with her or participate in any activities. She even called the probate court's Guardian Ad Litem (my MIL gave his number to her friend!) just prior to the hearing in which the conservatorship was transferred to a professional, and left a message on HIS answering service telling HIM that my wife can't be trusted. Since this woman has never even met my wife, I believe that this legally constitutes an act of slander.
I believe my MIL would be MUCH better off if she could not communicate with this "friend". I know we could block the number on her cell phone, but I have no idea if or how it could be blocked on the cell phone. It would also mean making sure no letters from my MIL could make it to the "friend", or letters coming from the "friend" made it to my MIL. What can we do about this trouble-making individual? My wife's lawyer supposedly sent a letter to this individual but it doesn't seen to have done any good. Considering this "friend" is 72 years old I wonder, frankly, if she also is suffering from dementia.