Continuity mistake: When Sam arrives home after the baseball game, she tucks her hair behind her ear twice between shots.
Continuity mistake: When the four girls are back at the graveyard for the third time trying to talk to Dear Johnny and put him back in his grave, they see the lights and the headstone float out in front of them, with nothing holding onto it. Then in the next shot there are chains around it, from the tractor that is holding it in mid air.
Other mistake: Really, that is one amazing tree house. Not only has it supposedly held up with no discernible weathering for over twenty years, but it manages to support four grown women, justifying their faith in bringing a newborn baby up there with them.