To ignore or reply? (new baby)?

You seem like a mature, responsible person. So just let it go. If she goes on with the rest of her crappy life thinking that you were jealous of her, who cares? You're having a fun filled, happy life while she lives off the satisfaction of other peoples misfortunes. So just don't even reply, just act like she didn't exist. You don't have to stoop to her level, just forget she ever happened and live your own life.