I could have written this post myself except that I am an only child and have no grandchildren!
Mum lived in a self contained granny flat in our garden and I took over all aspects of her care after dad died 9 years ago. Then just before March last year at my insistence she started to have two care visits a day. She resented it and complained daily but it meant I was able to get up at my own pace and spend a couple of hours with DH in the evening.
Unlike your mum my mum had never cared for an elderly relative and was always full of admiration for those who did. Although of course the things I did for her were not "care" as such, it was "just a little bit of help". A little bit of help that required me to dress her, wash her hair, take her to the toilet, prepare all her meals, do all her cleaning and provide company until 11 o'clock every night. Plus a dozen or so calls during the day to make her a drink, find her tv remote, change the channel, tell her the time etc!
All this changed at the beginning of the summer when mum had a fall and the carer thought she might have had a stroke. She was admitted to hospital for observation and 24 hours later I was in hospital myself having suffered an episode of amnesia with no memory beyond waving mum off in the ambulance! The morning I came home the hospital phoned to say mum was ready to be discharged but my husband told the OT that we were withdrawing all personal care and would not be available to assist overnight. This set off a further assessment and it became apparent that she was suffering from dementia.
What I had thought was her being stubborn, poor eyesight, poor mobility, inability to tell the time were actually all part of the decline of her cognitive functions. Three months on and she is still in rehab, waiting for a residential home. She still recognises me (and my daughter and cousin who are the other named visitors) but sometimes forgets that I am her daughter, thinking I am her daughter in law. She also forgets that I exist and thinks that my five children are actually hers!
I love my mum and my parents always did what they thought was best for me and my family but somewhere along the line the boundaries between us got blurred and I got lost as a wife and mother. It is very sad to see her so lost and confused now but it almost got to the point where it was her or me. Please, for your own sake, find a way to put boundaries in place so that you keep your sanity and your own life.