I can’t believe what I’ve just read. 
You need to find a care home ASAP and stop accepting being treated as a doormat by your awful mum. If she was willing to pay for and have professional carers helping, I could understand you letting her live with your family and trying to help her out. But to expect you to do the donkey work then to gift her major asset to your sibling because you can jolly well manage. Well, it beggars belief!
You are also not really thinking about the effects of all this stress on your husband, your children or yourself by meekly acceding to her demands. It’s really not on.
I remember my grandma coming to live with us when I was young and it was just awful. My poor mum was run ragged trying to hold down a job and care for us and HER. I found it hard to do my homework so went to the library straight from school most evenings, just to escape. I also couldn’t have friends round because Grandma was incredibly rude.
Grandma wasn’t a pleasant woman and yet the sun shone out of Aunty’s backside, even though she wouldn’t look after Grandma, her own mum. Aunty and Uncle had already taken what they wanted from the house when my Grandad died so there wasn’t anything worth having at this stage.
Eventually, after about 2 years, my mum had a mini breakdown so Aunty had to come and collect Grandma. Aunty lived in a large house and had never worked since getting married plus her son was grown up and living away so Aunty could have looked after her, if she’d wanted to theoretically.
Grandma was delighted about the change of arrangement and was a bitch about it to my mum...again.
However, Aunty simply collected her and took her straight to a nursing home more than 100 miles away where she died about 6 weeks later. They also arranged for her to be cremated rather than buried alongside Granddad, which I did think was wrong at the time but as a young teen, my opinion about any of it didn’t count.
Please stop and think about the longer term effects on your family OP. I know my mum bitterly regretted what Grandma put us all through but was also still upset that Aunty didn’t look after her at home as she initially promised to do.