Hands down the BEST gift my boys (1 & 3 yo) have received is a Family Membership to our local Children's Museum. It was a Christmas gift from grandmom and we go about once a month to the main location - Garden State Discovery Museum (Cherry Hill, NJ). Since it is a family level membership we can bring our family of four plus up to four guests. We can also use reciprical benefits at museums throughout the country for our family of four. We are fortunate to have three different museums within a half hour drive of our house. We also plan to go to two others when we make a trip to New England later this Fall!!!
It has paid for itself many times over!
We also have a Family Deluxe membership to the Philadelphia Zoo as it is a five minute drive (or 45 minute walk) from our house!!! We just upgraded to the deluxe as it includes rides on the carousel, train, animals and zoo balloon. :)
Memberships can be pricy but if a couple family members go in on them for your whole family to enjoy for a year that would be awesome for you!
I also fully agree with BOOKS!!! Books for now and books to grow in to - - - no better gift than that of an appreciation of reading!
Happy Birthday to your girls!!!
- J. :)