After Samantha defends Nellie and the girls against Eddie, Eddie is called by his mother to run an errand for her. Soon after he leaves, Samantha returns home and begins practicing piano but when she looks out the window she sees Eddie running around in his backyard with a kite. There is no way Eddie could have done the errand and returned home to run with a kite between Samantha leaving the Ryland home and returning to hers.
When Samantha returns home after defending Nellie and the girls against Eddie, she is practicing piano and when she looks out the window, she sees Nellie walking across the lawn with a basket of laundry while wearing a black dress and white apron. There is not enough time between Samantha leaving Nellie and her practicing piano for Nellie to have changed and begun her chores.
Also, as she would have been new, the housekeeper or head maid would have gone over with her what she was to do and therefore she would not have headed straight into chores, making it even less likely for Samantha to have seen her working while she practiced piano.
When Cornelia is about to toss her bouquet, we see her two friends stand in front of Grandmary. Yet when the camera cuts to Grandmary catching the bouquet, Cornelia's friends are to the right of her.
When Gardner kisses his mother goodbye after the wedding the brim of his hat is covered with rice, as he turns and grabs Samantha's hand there is no rice on his hat.
The flame on the candle during the dinner scene in New York differs between shots.
The coins in the money jar are recent, modern-day coins, not coins from the early 1900s.
Even though Samantha is said to grown up in the "Victorian" world technically she grew up in the "Edwardian" world, since the movie is dated in 1904, three years after Queen Victoria's reign.
When the teacher announces the essay contest, a calendar is written on the blackboard showing the current month of September 1904, with September 1 on a Tuesday. September 1, 1904 was on a Thursday.
Not only are the coins in Eddie Ryland's money jar new, several of them are Canadian.
You can see the camera man on the mirror when Cornelia is getting dressed for the wedding.
When Samantha first meets Nellie and her sisters, as she is leaving to go home she she says, "Goodbye Nellie, goodbye Bridget, goodbye Jenny." Nellie replies, "Goodbye," then the other two say, "Goodbye," simultaneously however in the story Jenny doesn't speak.