I am half black and white, father is black. our girl is like Mariah Carey. How do i take care of her hair?

Her hair is really rough to the touch but really long,wavy and blond. i'm at a loss can't treat it completly like black hair but not white either. Any good solutions to add softness and body with out making it gressy and heavy. By the way she's only 8 and can almost sit on her hair.Thought about cutting it but i think it would just become a short blond afro mess. Please someone with experience help[.