So sorry HImom - I hope she saw her life differently - I thought my mom had a good life but she was sure the complainer!
And on these notes, firstly, I didn’t make it clear, but it’s not my family, it’s my closest friend’s family. To be honest, if it were my family, my husband being around would help the situation and I would go there. But my friend’s husband is not around…
…rhandco- This certainly seems to be a situation in which you need to go there to see what is going on.
<<<<I agree. She is lucky she has time for a short while now.
…There are several things that are going on with your mom. She clearly feels the need for physical separation from your dad. She is perhaps tired or not ready for the caregiver burdens?
<<<<I agree. Definitely, but she has basically been caregiver for him for several years as in making him each meal (he won’t eat on his own), and I believe she is “done with it”.
…Might your dad be abusive? Mentally or physically?
<<<< Yes, her mom has told the dad’s doctor that he is abusive, but frankly it looks like Alzheimers or dementia, so those are known side effects. He is so very weak however that I cannot see any potential for physical harm. And he does not eat right and is addicted to pain pills (she isn’t sure how bad, but seems to be pretty bad).
…Maybe she feels she needs to move on with her life and is preparing for your dad to die soon. Is this a good chance?
<<<< This is where it is complicated. The mom wants to hold 100% of the purse strings. She doesn’t want to get divorced even though she clearly wants nothing to do with the dad - because of money. There are issues like the dad wants to leave 50-50 to each daughter, but mom has already given expensive jewelry directly to the local daughter Everything points to her mom wanting to move on for years and years.
…It sounds like your sister is your mom’s confidant and probably sworn to some sort of secrecy. Perhaps there stuff about your dad they don’t want you to know about. But, I think you need to be there to figure all this stuff out.
<<<< Yes, that is what she thinks. And recently there was significant health news from three years ago that popped up, and the mom acted like she never knew.
I am so sad for her, I am lucky that even my sibling who used to beat me is now relatively reasonable as an adult. But that family is so dysfunctional - dad is likely prescription med addicted, mom is likely bipolar. It’s like a horror story, and the end game is either he goes into a home (but that costs money and the mom wants to keep it all - supposedly she has more than enough for her to be comfortable indefinitely and him to stay in a home indefinitely) or he passes away.
There is also so much baggage from growing up and beyond - broken promises (please do not promise someone a gift of several thousand dollars and then reneg on it without warning), long tirade emails and apologies along the lines of “well I was only trying to help you”.
In a nutshell, she thinks her mom feels she is expected to care for her dad but does not (like going away for several days and not telling either daughter, and he cannot eat on his own), and anything the mom does is so no one will impugn her for “being a bad wife”. The mom also does not want to give POA to either daughter, because she thinks they’ll spend “all of her money” (when he was the only one working and she barely did a lick of housework or child care).
And that last thing is why my friend just doesn’t take him to live with her or to live in a home near her where she can help him and the mom is off the hook. “off the hook” = “taking away my money” to mom… 
And why is this any of my business? My friend has reached out to me, and seems to be near a nervous breakdown. Which would help no one. I cannot provide the physical support she needs over the next few weeks due to my own family issue.