We're going to a joint birthday party for a 3 year old girl and a 5 year old boy. It's a Peter Pan theme.

My son's only 7 months, so I'm not great at estimating what older kids would want. I'm thinking of making easy, no sew, DIY, Peter Pan and Tinkerbell dress up clothes. They would be tunic style (since I can't size them) and nothing fancy since it's this Sunday. Would that be a good present? If not, what would be? My go-to is books, what books would be good for kids that age?

Thanks!