Both of my kids are biracial. They both started out with very straight hair, especially my daughter whose hair was down to her shoulders and curly only at the bottom. Then around the time that she turned two it got curlier and curlier. Now, at 6 1/2, her hair is curly whirly and very soft. My son's hair got curly around 1 or so I think, as soon as it got a little bit longer it started to curl up. He is almost 4 now and has VERY curly hair but very soft and loose.
I love the element of surprise when it comes to kids and their looks. I thought for sure my kids would have black hair but their hair is actually light brown, even lighter than mine which is medium brown.