she actually become a hero, but if that's the reasoning might as well kill her when she's a child so she wouldn't suffer.
And yes the scene with the mother trying to reconcile is painted waay lighter than it's supposed to be. The MC still agrees to small talk, and even says about how she would hate her mother if she changed her demeanor (which she does, i mean c'mon she suddenly talks to her AFTER she was regarded as hero and gained the Light Spirit King's blessing). It's all because, despite the fact that her mother is the worst of the both, the MC she still sees her as her mother, so the MC more willing to "compromise".