So wait?? She's still not the real daughter it's just the body is one?? Chat I'm confusion

I have a hunch that she’s their real kid. Remember when the father said his daughter has a purple eyes like him and he compared it to her and she doesn’t have. However, the father also followed up saying it’s either she went under a magic experiment that could lose her both purple eyes. And our Fl went undergo with it! : D

No she is both in soul and body but her soul is of both a regressor and a reincarnator

Then why'd they adopt the other girl or whatever the comment section is saying?

They do adopt a fake in the novel, which I'm not pretty sure if she the OG FL or just a villain, but then they find a girl with the power of green after the dad dies who becomes FL and the older brother is a sub ML? I think
Tl is too choppy I barely understood the og novel plot