My situation was a little different because my mother was actually a very good planner and very organized. Over the past several years, she was even trying to go through her home/basement, anticipating there may be a point she cannot live at home. (There was still a good deal of stuff for my sister and I to go through once she passed away, though :)
Still, when she became ill last year, my boys were young and I was late in my pregnancy with #3. Luckily, I had some flexibility with my work to work from home for part of the day. My sons were in daycare because of my work so I didn't have to find someone to watch them when she needed to go to the doctor or when she was in the hospital. She lived alone about 10miles away and was still pretty independent but weak; she wanted to stay in her home. My newborn daughter was a joy for the nurses and other patients at chemo, and they enjoyed watching her rapid growth. It was crazy and chaotic spending much of my time in the car between her needs, getting my sons dropped off and picked up, the baby's doctor appts and groceries/errands for my own home.
You might want to look into adult daycare centers for your mom. Is your daughter home? If you can afford it also, it would be good to send your daughter to summer camp/preschool for a few hours or days per week to ease your workload. As your mother's disease deteriorates, it will become all-consuming for you. If not actual care, she'll need to be monitored for her own safety. You may have already spent a good deal of time explaining to your daughter why her grandmother doesn't remember things. I imagine it will be hurtful and difficult for your daughter when her grandma doesn't remember who she is.
I agree with Tracyxo that you should at least look at some facilities, maybe not now but your mother's care may become too much for you to handle alone and manage your own family. (You still need to visit daily to keep them on their toes.) You can't beat yourself up over placing her in a facility if it's truly the best thing for your own health and everything you have to juggle and manage, especilly as an only child. My mother received wonderful care at a facility for her last 2wks in palliative care. She had terrible pain that "evolved," and I don't think her pain management would have been as immediate or effective even with a 24-hr caregiver.
Best of luck to you.