So Eun Seong is the first wife's baby? That…

So Eun Seong is the first wife's baby? That makes more sense. I was getting confused as to what revenge for her family she needed to take cause the mistress is a totally manipulative cow. I also didn't understand how no one was realing that the son was a girl because it lived in that house cor like.. a week. I think i can start to see how this is gonna be a confusing story xD