I don't think it's a loss of a child just because in the second episode, Malificent said the EQ would've been married at the same age as Snow White but that didn't go through. Now we know she also blames Snow White's father, I still think it's a love of her life thing.

OR

I can't help but wonder where Snow White's mother is. If she died in childbirth, then by proxy, one could blame Snow White. And maybe her mother is related to the Evil Queen because Snow White isn't surprised that the Queen wants to kill her despite the whole comfort scene.