One of the comments said to not use the brain while reading this. I get it after I read the ending. Better be brain dead as you read. At least you can lessen your curiosity over abrupt ending. It's a FREAKING CLIFFHANGER ENDING.
Don't let the plot deceive you. I agree she can get the hell out but who knows the creator might be as one of the psychopath authors who take pleasure in killing off everyone's favorite character. I'm still traumatized by this action.
The mother just gaslighting Shinwoo's emotion. Then the stepdaughter come just to make it 'clear' that the mother is suffering.
The twisted plans is to let the mother let go her burden emotional mental health to be a normal-non problematic mother.
So yeah, idc whatever happened to her, I just wish she gone from the plot. She is the reason Shinwoo has a lot of undone knot with his feeling.