Great gesture OP!!

You sound worth your weight in gold as an employer.

If you're sure they celebrate Christmas, what about Christmas pajamas?

Its a very nice gesture OP. Maybe a new DVD they might like, or a Christmassy themed one, Books are hard unless you know what kind they like.

Very nice of you, OP.

I think that's a great gesture, just keep it small so it doesn't accidentally outdo any of the actual family members' gifts. Maybe books or a board game to share?

In addition to her bonus (a week's pay), I'd like to get a gift for each of our nanny's two young children (both under age 8) for Christmas. Is that inappropriate (mixing the personal/professional relationship) or a nice gesture?