was this DIL raised in a 'throw-away' family? She may actually have no concept of family heirlooms - you might mention - in as nice a way as possible - that this, that or the other thing was made with love etc and if she doesn't want to keep whatever it is, that you'll keep it at your house until such time as grandchild is old enough to treasure it ....
I've noticed that this latest generation (teens/early 20s) are so used to walmart mentality - "get tired of it - pitch it, buy something else"..
it applies to linens, dishes, clothes, just everything - people no longer treasure anything - it's cheaper to pitch/replace than repair...
whew, crawled on my soapbox there for a minute...