My paranoid mother won't allow help with taxes or finances. Advice?

Here I am, on the Forum again! Previously, I had asked a question about complicated taxes. My mother is 85, has an undiagnosed Personality Disorder and perhaps the beginning of dementia. She is strong-willed, stubborn and non-compromising. She had always been sure that people were "after her money".

Now it is close to tax time. I've had a hell of a time trying to collect the various documents needed for taxes, because I believe she loses them. To make things even more difficult, my mother trusts almost NO ONE and won't allow me to take her taxes to a CPA or tax attorney because she doesn't "know them personally". Well, of course not. Meanwhile, she waits and waits for a family friend/attorney to give her advice and it isn't forthcoming. The clock is ticking.

As for her finances, my mother looks very well-off on paper. But hardly anything is "liquid" right now. She knows she needs to go to probate to get my dad's stuff signed over to her, but again, she won't do anything because she doesn't "know the probate lawyer personally."

I have tried over and over to convince her that she needs to get to work NOW...yet she keeps waiting for the family friend/lawyer. What if he doesn't come through? How do I get her to do these things? I am worried sick that all the funds my dad accrued during his working career will go completely down the tubes due to late fees of taxes, waiting on probate, not trusting the financial advisor, etc. etc. She is going to lose it all. Please, please advise!!