Here are a couple of screenshots of the children of Roger and Mia Rao, from Barnacle Bay. I took these from my Random Town Jump. They're currently at the Teen stage, but their appearance shouldn't really change that much as Young Adults.
The oldest child is Zara Rao, the child that Mia is pregnant with at the start of the game. She inherited her mother's hair and a good deal of her looks. I believe the eyes are Roger's, but I'm not entirely sure.
The middle child is Zander Rao, who managed to get the default black instead of either parent's hair colour. He doesn't really look like Roger, so I guess he inherited his mother's features.
The youngest child (and the heir) is Zelda Rao. She looks very much like Zara, except her hair comes from Roger, not Mia. Roger's hair is black with brown highlights, whereas Mia's hair has a brown base and black tips, highlights, and roots. The colours look very similar, but they are subtly distinct.
