Helen10, I have just read through this thread and my heart goes out to you. It is so difficult being torn between minding your mum and your little girls. You have been doing amazingly. But maybe something has to give for your sake.
The guilt is huge when you allow your mum to go into care, it’s a whole other kind of difficult. It’s hard for you given what she said about caring for her own mum. I have made it absolutely clear to my kids that if I ever get Alzheimer’s, I don’t want them to be my carers and I want to be in care. I don’t want them to ever experience the stress, panic, awful sadness and guilt that I have. My mum is in a specialist place and while I understand your concerns about distance; it still might be the best thing for your mum, hard as it would be for you and your Dad. With FaceTime available, he could still see her regularly, most places facilitate this. But this is so much for you and your family to take. I was away so much with my mum(she refused to leave her house) that my youngest girls really suffered, when I got back at night I was too exhausted to think and I wasn’t there for them as they needed, which added to the guilt. I think you just have to accept the guilt as something that comes with the territory and keep reminding yourself of everything you have done for her and your dad. Which is a lot. Mind yourself.