Daisy, I'm slightly out of touch having been without internet access for some time.
If I'm reading this right you have two adult children.......the son who sent you "to your room" and the daughter who thinks it's your job to babysit her children so she can live her life as she wishes.
I don't have any grandchildren (that I know of) so I don't have the insight that others on this board do but it sounds to me like you need a break.
Olive brand to your son?? not on my watch.........and I too have learned the hard way not to stay with family when traveling even if they would be insulted if you stayed elsewhere (like at home). Too bad you didn't call 911 while you were in the room to say you where being held captive.
I would give the daughter notice that the Day Care Center is closing, and be prepared for the tantrum she throws when she realizes that she might have to be financially and otherwise responsible for her offspring.
I think the bottom line for me is that adult children who treat their parents like servants (or worse) aren't people I have any time for. Accepting the reality is a sad and difficult path at times, the disappointment of a lifetime however if they want a doormat, they can go to KMart or Walmart or wherever and buy one.
Get ready for the adult tantrums, and unfortunately they will use the grandchildren as pawns if you decide to find some time for yourself.