I'll try to get them as close as possible. Don't worry. Some of the children's facial structures (mouth, chin, eye) are inherited from Pearl. Soda Pop inherited his nose shape from his father. So, most of the children look like their mothers so it won't change much. I'll compare their faces with Pearl's face and alter certain facial structures of their fathers in order to get the offsprings look exactly as they were.

ETA: I compared the children's faces with Pearl's face and I wrote down the facial structures that are inherited from mother and the facial structures that are inherited from father. Then I cloned the children in BodyShop, aged them up to adult (changed gender if necessary) and changed some facial structures to match with the faces of the sims you've recreated. I didn't change any facial structures which the child inherited from their parent.

Anyway, I tried it out in the game. I reroll the pacifier and the children looked exactly as they were. Yay!