E.C.
If you want to get a shared item, I think I'd lean towards something like books. But as a mom of twins, since multiples are so often referred to as a single entity rather than individuals, I'd lean towards getting 3 small things over one larger thing - and for 1YO's, if you have a Costco near you, you could get each girl a similar-but-not-matching sundress, romper, or jammies for very reasonable prices IMO. Or get each girl something like a sand pail and shovel maybe with a few practical items inside (toothbrushes, shampoo, etc.)