I think Elsa was born with her powers. One possibility is, that it runs in the family (maybe mother’s side, female side) but surfaces only rarely. The Snow Queen might be her aunt, and it showed in her as well. Another possibility: Elsa’s mother was pregnant with her when she accidentally or less accidentally was frozen by the Snow Queen, who might have been even her sister. The mother’s true love, who she just had married, the prince of Arendelle, and father to Elsa and later Anna, saved her by an act of true love. But their firstborn because of these events got the ice powers. (not inherited but still born with it)
Interesting theories. Yeah, I really hope the origin of Elsa’s powers are explained more on Once vs. the movie. I like Frozen, great music and all, but that was the one thing that I felt was seriously lacking.
Not liking the idea, to give Elsa a different mother, of making her the daughter of the Snow Queen. Normally I am all for not limiting family to blood related, but in this case, because of Elsa’s special power, it would feel like a cheat. Elsa is different, oh, but she was adopted, that explains it all. No, sometimes it’s not that. Sometimes you are of the blood, or genes, of the same parents, and very different from them and from your siblings. Sometimes you feel so different, that you feel like you have to be of different parents, it can feel like an odd relief to imagine, you were adopted, but you aren’t. There are no other, biological parents out there, somewhere, who would understand you better, just because they are of your blood. You are who you are and you might be very unique in your family, but you are still blood related family. That is a feeling I sense in Elsa’s story, and like, and I would prefer to keep it.
I’ve been trying to think of why I was not on board with the adopted theory and this is why.