Thanks so much for the ideas! I knew you would help!
Many of the things I had thought of were either not appropriate b/c DD (age 3.5) wouldn't know what they were or we didn't have on hand (like jacks, or jump rope). I'll throw out some options (jelly, juice, Jell-O) and let DD pick (but I know she'll pick Jell-O because the letters are so big and bold on the [ackage and she will want to spell them out).