This is how my hair is/was. I just recently got a keratin treatment to smooth out my curls, but I know my mom had a really hard time with my hair when I was little and I hated my hair in grade school. I started kind of figuring it out freshman year of high school, and I got pretty good with it by the end of high school and into college. Your daughter is definitely too young for a keratin treatment, but when she gets older I would definitely let her get something to that effect, if she wants it. It has made life so much easier.
Also, keep in mind that as a girl, he hair will be a vey sensitive subject. I was always wishing I had straight smooth easily manageable hair like "everyone else" at school. So... I will give you some pointers from my experience and hope they help.
1) always use conditioner in the shower to get the knots out and they won't ever get out of control.
2) I could never brush my hair, because it would just get frizzy. So, in addition to getting it smooth in the shower with conditioner, I would just go through it with my hands when I got out of the shower.
3) Never layer her hair :o) It just makes the frizzy problem even worse. And then it goes in all kinds of weird directions.
4) She may be too young, but a good flat iron will come in handy for her one day. Use some kind of spray to protect her hair from the heat.
5) a little bit of mousse or hair gel will tame her hair down and control that big frizzy look.
6) i let my hair air dry, or just point the blow dryer down on low to let it dry. my friends and boyfriends always thought it was a hilarious sight to see me after blow drying my hair--which i only ever did for the comedic value.