I saw the film approximately a decade ago so I don't remember it super well, but my recollection is that it's close relatively close to the book - certainly it got the spirit of the book right.

In the movie Ruth and Idgie aren't as clearly together as they are in the book, but my recollection is that they're not not together - the movie doesn't say it's a romance but it also doesn't try to stop you from reading the romance just below the surface.

And I actually preferred the movie ending. The book sort of trails away at the end and the movie goes out on a stronger note.