K.G.
Maybe finger painting with washable paints and a heads-up to parents prior to the party that attendees should wear clothes that are appropriate for the activity? The wee guests could also make something for the birthday girl by making handprints on a large piece of poster paper and then writing (or having mom,dad, or an older kid write) their names next to their handprints. Maybe the older kids can be helpers for some activities. Also, kids are amazingly good at coming up with their own games to play. Twister might be fun for the older kids.