Scented geranium (Pelargonium) is a nice idea.
Lamb's ear (Stachys byzantina) is really fun for kids, very soft and furry, perennial, but prone to mildew when the leaves stay wet too much.
Plectranthus amboinicus aka Mexican mint, is another furry leaf thing with scent, not so easy to mildew, can be green or variegated.
