Hi Martha,
Does Bill give your Mom her medicines or are they in one of those daily dose plastic containers for her to take herself? It no longer safe for your mother to be responsible for any of her medicines. She's done far better than most of the population, but her turn is over!
I'd say the time has come for your mother to see only one dose (the pills she's to take at that time of day) of her pills at a time and be watched while taking them. That's how the aides at the assisted living facility did it for those residents who needed that help. Bill can tell her that the doctor called with the instructions to take them all. Repeat that same process at the time the next pills are to be taken, ad infinitum.
Yep - you knew she was stubborn!! You saw it up close and personal for several years and it got worse and worse over that time. Poor Bill and Anna, but they had a good idea of what they were signing on for. I'll bet they couldn't begin to guess how different your mother's personality was from Anna's mother's personality and how AD would make their behavior differ. Maybe their caregiver roles are far different, too?
If your mother stops taking the medicines, she could be back in congestive heart failure or whatever heart trouble she had. At her advanced age and increasing dementia, it would be questionable whether to be so aggressive with the treatment that was given her several years ago. Sad, but true.
Hope you're still enjoying all the lovely things, adventures, joys, and new friends that your life now holds!
Blessings - Barbara