Continuity mistake: During the fight between Roberta and the bully, at the softball game, the crowd of children around them change many times between shots. (00:52:50)
Revealing mistake: You can see the round stage/set lights reflected in Morton's glasses, when he jumps from the fence to go over to Chrissy during the softball game. (00:51:55)
Continuity mistake: After the fight at the softball field, Sam is riding home on her bike and both her cuffs are unbuttoned. Then she opens her front door and walks in, and her left cuff is done up. (00:53:25)
Continuity mistake: When Grandma is cleaning the floor, you can see the plate of cookies is on the table. Moments later when she takes the girls cups from them, the plate of cookies is on the serving tray. (01:11:50)
Visible crew/equipment: When Sam is trying to get the bracelet out of the sewer, the bracelet "falls" off of the ledge. However a wire is clearly attached to it, giving it a tug to make it appear to fall. (01:05:10)
Continuity mistake: When Roberta apologizes to Chrissy about faking her death, her stringy, wet hair goes from being tucked behind her ear, to hanging in front of her ear, then tucked back behind her ear. (00:34:35)
Continuity mistake: When Sam's Grandma brings in the tray of lemonades, she picks up two glasses of drink, but in the next shot Teeny, Chrissy and Roberta all have a glass. (01:10:40)
Continuity mistake: In the diner, Sam bends her straw down twice. (00:18:35)
Revealing mistake: At the dinner table, when Bud knocks the glass of wine over, and the wine spills all over his shirt and trousers, a large red wine stain is already visible on his white shirt, before the glass is even knocked. (00:55:25)
Continuity mistake: When the girls see crazy Pete for the first time he cycles past the camera. then the camera flashes to the girls and then you see the exact same footage of Crazy Pete going by on his bike.
Audio problem: When the girls paint the garage, the Wormers come along. One wormer says to Chrissy "Maybe it's your armpits, lardbutt," but his mouth says "lardass." (01:09:00)
Continuity mistake: When the girls are at the diner, talking about how the waitress Wiladene is "off", Teeny has one hand on her Cosmo and one holding the pencil marking the answers, but in the next shot when Teeny says "What do you expect? She's a witch" her hand is just touching the edge of the table.
Continuity mistake: In the diner scene, the red can with the treehouse money in it repeatedly jumps around, from the table, to the counter behind Chrissy. (00:19:10)
Continuity mistake: When the girls are riding their bikes to the library, Chrissy's hair is up in pig-tails with pink bows. In the next scene when the go under the train bridge, her hair is down without any bows. Then when they come under the bridge, Chrissy's hair is pulled back into the two pig-tails with bows. (00:28:25)
Visible crew/equipment: The shadow of the camera is briefly visible on Adult Roberta, when they play red Rover at the end of the movie.
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.
Continuity mistake: When they are at the Greenfield Library, and Roberta is reading an article involving her mother's death, the paper is alternately flat/wrinkled between shots.
Revealing mistake: It is obvious that when Sam is in her bed reading her book with a torch, that a set light is being shone at her face and that the glow doesn't come from the torch, because she turns the torch away from her and puts it on the bed, but a soft glow of light remains on her face for some seconds. (00:20:20)
Audio problem: When the girls are climbing up onto the roof to get in Sam's grandma's attic, Chrissy says "We could get in trouble for this," but her mouth moves to a different line. (01:12:25)
Continuity mistake: When Teeny gives the War Veteran a drink, when she hands the bottle back to Chrissy, she changes from holding it with the bottom of the bottle toward Chrissy, to holding it with the lid pointing at Chrissy. (00:43:20)
Answer: Reshooting certain scenes would most likely necessitate new stunt people, as the first one(s) would most likely be hard to get back.