I still think BroSwan could work because what Emma thought she knew and what happened might be different. Maybe Bro Swan is from another home later on too, if not the boy who she thought replaced her. Maybe this is not the first time he tried to contact her but before she was not ready to let him in, to listen to a story that sounds incredible until you believe in magic.
I wonder if Emma was viewed a bit as a scary child, like in a Stephen King novel? Did her magic freak out potential parents? Did she run at some point thinking a family would not want her but they did? There was somethin in the newspaper about her criminal past but we could not quite see it, just tragic set of events if anyone remembers. I always thought she first got on the criminal path trying to protect someone, maybe this guy.
Or maybe he is the one who taught her how to steal cars. Endless possibilities and months to speculate.
“If I had a world of my own, everything would be nonsense. Nothing would be what it is, because everything would be what it isn't. And contrary wise, what is, it wouldn't be. And what it wouldn't be, it would. You see?” -- Lewis Carroll, Alice's Adventures in Wonderland & Through the Looking-Glass