About the only thing I can share on this one is what My mother had to do, in your situation.
She politely told my sister that because of her age, it was becoming very difficult to be able to handle, and have the patience needed for youngsters anymore, and as much as she wanted to carry on helping, she had to decline.
She also told her that there were things that she wished to do, now that she was older, and could not do them if she was babysitting. Such as travel, day outings with freinds, quiet time, etc. My sister was not pleased, but got over it.
My sister found a very capable sitter, and the problem was solved.
You have a good day my freind. Thinkin of yu.
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Easy Does it..Keep It Simple..Let Go and Let God..
Hi, I'm new to this board but I had to respond. My mom has 16 grandkids and she sat all us girls down very early on and explained to us that the reason she had her kids when she was young was because she had the energy required to raise the 5 of us. When we started having babies we knew that we were welcome to bring the kids over to visit, but we had to take them with us when we left. I don't think any of us were offended that she or my dad had other things to do.
I hope it works out for you, I wouldn't wish 2 babies in diapers on anyone. :) Good luck!