I’ll be honest I had no idea what Regina had against Snow in FL. I may just be dense but I was just so stuck on the fact that the Evil Queen in Snow White hates her because she’s the “fairest of them all”. Obviously in this show if you get stuck on original fairy tales, you are not going to guess anything. Brilliant.
So clearly this backstory was important so that the audience could see that Regina’s anger was human – it wasn’t just jealousy about beauty. It was anger for her indirectly taking away her love as well as getting the Happily Ever After that Regina always wanted, where she could be with her prince.
In my opinion, though, i do not think that Regina killed her mother. As we’ve seen in this episode, even when Regina turns completely cold, she is human. Her anger towards Snow is based in human anger, not just out of evilness (though she is 2000% evil). I think it is that innate human side that prevents Regina from actually killing her mother. She couldcertainly find a way of banishing her (hint: queen of hearts??) and I do not doubt that the powers she gains were taken from her mother (stripping her of what makes her “powerful,” for lack of a better word). She wants her mother to suffer the way she did. But i think it is something about this untouchable, innate bond the two share that prevents Regina from killing her.
This episode was absolutely vital for the series as a whole, and it was about time they showed it. I’m also so happy that they made it so you could understand why Regina hates Snow (misdirected and clearly illogical) but it doesn’t taint our feelings of how pure and wonderful snow is. Even as a child she meant no harm. In fact she loved Regina and actively wanted to help. Job Well Done. And lets see more of Regina’s mother, thanks.