i dont get it why would she adopt a kid who looks exactly like his son?

uhh idk if this is rhetorical question or genuine but she was pregnant with twins and she lost one of them. the one who survived is jaewon (their biological baby). but when she saw seoin at the center, it striked to her how similar seo in looks to jaewon. so she adopted him. replacing the baby she lost, ie, one of the twin that died.

i get noww thanksss