My mother-in-law is very short, dark skinned, with black hair and dark eyes (Gypsy) and all of her grandsons (my boys) are tall, fair and red-haired. You would never guess they are related to her.
Genes are always a mystery to me. My granddaughter looks like my late mother-in-law when she was her age, same shaped face and pouty mouth but she has her mom's teeth structure and smile. Interesting combination. I love mixtures. My dad had dark hair, almost black when he was young (Norwegian) and all of us grew up with blond hair.