Adam said we’d find out more about Emma’s past in the first half of S3, which encompasses episodes 3×1 -3×11. We already know that the first 5 episodes are going to feature certain characters:
1) 3×1 features the entire cast, but judging by the title, focuses in on Henry a bit.
2) 3×2 is supposed to be classic Snow and Charming.
3) 3×3 is going to be Regina specific (with a bit of Tinkerbell added in).
4) 3×4 will be Rumple-centric, but will probably give information about his history with PP.
5) 3×5 will tell how Killian Jones became a pirate.
6) 3×6 will introduce Ariel! I suspect, however, that we might find out some about Emma here (but could be wrong).
7) 3×7, is a mystery, but we know Wendy Darling appears in it, and judging by the title “Dark Hallow” could be about Peter Pan in NL.
"That’s how you know you’ve really got a home. When you leave it, there’s this feeling that you can’t shake. You just miss it." Neal Cassidy