Kaylynn Langerak genetics

I have a doubt that won't let me sleep. My Kaylynn ended up having children with a random blond-haired townie, but all her children have ended up coming out red-haired, except one with black hair. How is it possible? I understood that Kaylynn is genetically blonde but I don't understand how almost all her children have come out red-haired without having that gene. Is it normal?