As an artistic person myself, I would love something like very nice art paper with pastels. (softer than a crayons), or water colors.
Also, Sculpy, the brightly colored modeling clay that is infinitely creative. I used it with my kids when they were little, and this last Christmas my teen & I created an entire Nativity set ...very fun with the bonus of being mind & time occupying...
It is probably easy to find out the restrictions from the facility itself.