Thanks
@LadyLouise - I think I need to clarify the position on finances properly so it's clear. I think her mom only worked once they were a bit older so her contribution to the joint savings would have been smaller and maybe that's important. The issue with control over the financial side by my partners dad is that she simply isn't able to communicate her wishes anyway (though I think this was long before she had demensia - it always seemed like an excercise in guessing how to make everyone else happy). She also really doesn't like having help in the home apparently and generally refuses help or ignores the person.
I hope she softens to receiving the care... She's otherwise a healthy individual and it seems a real shame to have such an unhappy period of her life when she could be getting help from people trained and that genuinely care for her happiness.