I think that all day long we prioritize just as we did when we were working. I choose to be busy I always did but the activities may have changed a bit over the years, eg I no longer dance but I do knit lace. I am in a position where I can juggle priorities yet stay busy. I would love to be able to stop in the afternoon and take a nap in the afternoon especially as my doctor has been trying to get me to do that for some time but it just doesn't work for me, I get impatient watching the clock.
My activities are decided by my pain level at the time, yesterday apart from the usual stuff I baked a ton of shortbread and did a lot of embroidery, not a very active day. Today I have shoveled snow twice, that's pretty amazing for me but tomorrow I will pay for that. If I needed to baby sit a grandchild I would do so but it would be on the clear understanding that the activities would be what I was capable of on that day. If I had to run around after them it is likely I would struggle but if we could paint , read, bake or do crafts I would in all probability be OK.
I think we need to consider these things before we say yes or no to babysitting.I would not be able to do it on a regular basis but in an emergency I would cope even if I paid dearly for it the next few days.
I would never complain about being busy, it is the way I choose to live, I enjoy a busy life...and I do have a crippling illness but one does what one can up to ones own limit