"[Mackenzie Foy] is really a fantastic actress and she's very professional, but she is still a kid and that's really nice to see, whenever there is a balance and they're able to have fun and play on set, but still go home and hang out with friends her age. I was really impressed with her. I think the biggest change for us is that we had a "swear jar." And she was rich - she made more money than us."