if you're not wanting ti single out specific carers in an obvious way, i would simply make sure you put a personal message in a Christmas card - words of appreciation mean a lot more to a day carer than any amount of "stuff" you can give them.

my mum used to do FDC, and each year she'd get the typical things (bath stuff, little hampers) - nothing huge, and it was ALL appreciated - but she still has the cards with the special messages in them now. i am the same - i hold onto messages - stuff gets used and is gone kwim?

if you need help with how to word your appreciation, i'm sure some of us on BB will give you a hand - there's a few of us with a creative wording streak!