Trivia: Henry's sister in the film is really Quinn Culkin, Macaulay Culkin's sister in real-life.
Trivia: The photo of Henry's dead brother Richard, is that of Macaulay Culkin's other real life sibling Rory (seen in the movie Signs).
Trivia: For the treehouse sequence, young Macaulay Culkin and Elijah Wood made the 30-foot climb up the tree themselves, with no safety nets or wires. However, the tree was mostly surrounded (everything outside of the camera frame) with elaborate scaffolding, sufficient to support all the camera crew and equipment, so the boys were always within arm's reach of an adult.
Trivia: Mary Steenburgen was originally supposed to play Susan, but had to drop out when the production was delayed.
Answer: Yes. She had to drop out when production was delayed, and she was no longer available.