I've never had this issue until just recently. It seems like now in every family there's at least 2 or 3 duplicates that aren't twins or triplets. I have had one family where every kid came out with the same hair. I think it might just be some crazy coincidence. From what I can tell, the parents definitely play a part in what the children look like. For example, I had a blonde married to a redhead and every child came out redheaded except for one that came out blonde. And in many cases, I get kids that look like their parents.