It was a puzzle.
Eventually, I asked her family (parents, grandparents, aunts, uncles, and cousins) to tell me stories about her, and I alternated story squares (which are striped) with regular squares. Each story square contains a word, and part of her gift was a paper explaining what story went with each word.
Here's a close-up of one of the words:
I tried using iron-on transfers, but they were less than successful. Only a couple of them survived.
It always amazes me how much the sashing helps make a bunch of discordant, unconnected squares seem like they belong together. Compare the three columns on the left with the two on the right - the ones of the left looked just as jumbled before I added the sashing.
Here's the end result (upside down, just because):