I think grandma 2213, you are being taken advantage of. At the age of 70, I am currently helping my daughter who has a two month old baby.
I go to her house twice a week, early in morning so she can go back to bed for a few hours and catch up on sleep.
While I love looking after Gson, I feel absolutely knackered when I get home and put my feet up.
I certainly wouldn't, or couldn't do it for any longer. All the bending down to change nappies and burping etc, really does my back in. Unfortunately he has got severe acid reflux and doesn't sleep an awful,lot. But hey! If we can help, we will, won't we?.