Oh good gried... No More Mommy Guilt!! Your daughter will never know - or care! Your son might say something, but a 15 month old still wouldn't "get it". This might be the last year to get away with it, though, because if your son tells her "that used to be mine" next year, she'd "get it". You can always give used toys, though. We only buy 1 or 2 toys new each year... the rest come from garage sales or kid resale stores (the local mom & pop store that's a version of Once Upon A Child is my favorite). I buy stuff all year long when I see good deals and store in the 'gift closet' in the basement. We wrap the presents (Santa only brings small toys for the stockings here) even if 'gently used'. Even the new toys are out of the packaging and then wrapped. Nothing frustrates a small child more than unwrapping a box and then having to wait 30 minutes for a parent to assemble it!