A conversation is used for one scene. And in case you didn’t read carefully or wasn’t aware, Ginny and Josh have been filming for more than one day. This clues us that they have more than one scene. Yes, this conversation you thought of could be part of it, but judging by the days of filming, it wouldn’t be the only one for Gosh.
Personally I think it’s two scenes:
1) A scene with Henry in which they impart some sort of advice or wisdom or helpful clue that helps Henry with whatever is happening post-Gothel. This scene will also double as a way to check in with Snowing in general (how’s baby Snowflake? How’s Storybrooke? How’s life?)
2) The coronation scene (or what some people are predicting is a coronation scene) with the whole family. They likely have a more active role/speaking lines here than JMo did since it sounds like she’s only in a few moments of this scene. They just couldn’t film at the same time as JMo because of their pilots on NBC/ABC.
The first scene would take a good number of takes to film (possibly a whole day) and the second wouldn’t take as much since the coronation scene is big and involves many different vignettes.