I agree that board games are good. My dd really likes cariboo, don't break the ice, my first uno, candyland, etc. Definitely art stuff is always a likely hit. I think a little outdoor fun kit could be fun. Throw in some sidewalk chalk, a kite, some bubbles...maybe put them all in a sand pail with a shovel. My dd would love to receive that and it wouldn't cost much.
ETA: books are big hits here too. Not only does dd love to be read to, but she loves to gather all her stuffed animals and dolls and "read to the children"
Good luck!