My 11 year old helper is amazing with the kids.

Wow. Well, we have a consensus: nannies of all ages do, in fact, play with their charges (a crucial part of development) and OP should definitely not be a nanny. Also, sometimes grandparents do odd things with their grandchildren. I used to play ‘puppy’ with one of my charges (not remotely close to the story of the grandmother) and I HATED it, but played it all. the. time. Because that’s what we do, and we add in education without our charges even realizing it. Happy nannying, ladies!