Yes R27, but that is the only scene which does this. A bunch of other scenes make it clear they're different people. Copied this from IMDB:
1. Ninny states in the nursing home during her first scene that she was practically adopted by the Threadgoode family, not born directly into it.
2. Ninny Threadgoode also states that she married Cleo Threadgoode, another one of Idgie's brothers. However, Cleo Threadgoode never appears by name in the film, and neither does Ninny, so the confusion is understandable.
3. During the wedding scene near the beginning, a child-aged Idgie is on her brother Buddy's back while Ninny says in voiceover that she (Ninny) had always had a crush on Buddy, rather than "Idgie always had a crush on Buddy." Even if she was trying to pretend that she and Idgie were separate people, it doesn't seem likely that Idgie would describe herself as having a "crush" on her own brother.
4. Towards the end of the movie Ninny says that Sipsey confessed on her deathbed the full truth of Frank Bennett's death. Idgie knew the truth from the beginning, so Sipsey would have no reason to confess if Ninny were Idgie.
5. Mrs. Otis, Ninny's friend and roommate, was also present at Sipsey's confession, meaning that she would know both Idgie and Ninny if they were separate people. Mrs Otis' adult daughter confirms that her mother has been Ninny's neighbor for many years. Even though we never see Ninny and Mrs Otis interact in the film, it seems likely Mrs Otis would have noticed that her long-time friend "Idgie" was suddenly calling herself "Ninny."
The implication that Ninny and Idgie are the same person, therefore, is impossible based on several other points in the film.
The book makes it clear that Ninny and Idgie are different people, as Ninny has died and Evelyn is visiting her grave when she finds the jar of honey and the note on Ruth's tombstone. A final scene confirms that Idgie now runs a roadside stand with her brother Julian (the boy who made fun of Idgie at the wedding), where they sell honey while Idgie entertains visitors with her tall tales.