What a Time in Storytime when we worked together. And I bet she may have stumbled across the idea from the "Great Brain" of the pubyac listserv, my go-to listserv for ideas, discussion, support and rants on all things public library children's and teen!
Here's how it works. You hold a storytime/sleepover for kids' favorite stuffed animal. Plan to hold it in the evening or late afternoon 60-90 minutes before closing time. If you are in the mood and do pre-registration, make simple nametags for kids and critters or wing tags with address labels. Find a sheet or blanket and a few pillows and set up in your story area like a bed. Read a few stories to the kids (I used Don Freeman's Corduroy and adapted Megan McDonald's When the Library Lights Go Out). Then we tucked in the animals and read Margaret Wise Brown's Goodnight Moon in big book form. The kids kissed their friends good night, we turned off the lights and out we went.
Once the families left, we used a digital camera to take pictures of their stuffed animals having fun in the library: peeking in the bookdrop; in a display case; reading books on shelves; answering the phone; checking out books and generally having fun. In addition we posed all the animals together being read to by my "Teddy Dragon" and posing with a big stuffed animal we have at each library. Then we quickly printed a page for each child that had the two group shots plus a photo of their very own friend.
The next morning when the kids came back to pick up their animals after the sleepover, they were given their photo sheet and were absolutely bug-eyed thrilled. It is a simple program that yields great results. Ambitious programmers could also add a little diary of events for the kids to make it even more special.