OK. I'm slowly piecing things together but what doesn't make sense is Cossete's age. If she is the daughter then shouldn't she be older than Keira? C supposedly manifested her powes on her 18th birthday but Kei is already 18. If her mother is the first wife then shouldn't she already be 18+?
Last panel Keira be like: "well hello too you evil wench, decide to show up again to ruin my live huh? You witch from hell why don't you just stay in your cave. I hope you just explode."