Other mistake: In the scene where Carrie is reading bits of love letters to Big, she reads from a letter from Napoleon to Josephine and uses the line "I awake consumed with you".In Napoleon's actual letter he wrote "I awake filled with you" and for a brief moment you see the book Carrie is reading from, which shows the correct text. (00:22:05)
Other mistake: Charlotte's dog had puppies during the show's final season and in the last episode we saw her and Harry walking them all. All the pups looked like pure-bred Cavalier King Charles spaniels (like their mother), even though they were mongrels. In the movie, the dogs are completely different and appear to be long-haired Jack Russells.
Other mistake: In the "fashion show" that takes place as Carrie is packing, neither Miranda nor Samantha could even begin to fit into Carrie's clothes.