OUAT: Who is the Snow Queen to Emma?

Wanna build a monster snow man?

                 It's clear that the Snow Queen came to Storybrooke of her own accord but for what reason? It couldn't have been for Elsa. Elsa was stuck in that vase, a vase that the Snow Queen probably put her in to begin with. It must be because of Emma.

The look on her face suggests the Snow Queen knows Emma
VERY well.

           The way the Snow Queen said Emma's name was not malicious at all. It was more of a mournful sound. She had the same look on her face that Regina did with Henry many seasons ago. An almost motherly look. But where would Emma have met her for the Snow Queen to develop that sort of attachment? We know that Emma is magic. It could be that in her early years like when she was 3 or 5 she tripped into another dimension or had a dream of escaping her horrible childhood and so wandered into another world in her sleep. It's possible Emma met the Snow Queen in some other dimension and melted that heart of snow to create a parent-child relationship. But then something happened that took Emma away and she doesn't remember.

I love that jacket!

         It could be none of what I just said but like I said it's a guess and if I happen to be right then kudos for me. The Snow Queen reminds me of Regina in her early evil days where all she wanted was a family and her vengeance. Also Rumplestilskin is in on it. Sooner or later the cat will tear its way out of the bag and surprise everyone.