What a beautiful little girl and her hair and hair color are amazing!
My daughter is 5 and I cut her hair (mvself) twice. Every time it grows in a different state! the first time it was baby hair, big wild curls, I cut it off and it came out really tight ringlets, I cut it again last year (she was 4) and it's growing now as this loose curls, still curl but looser than it was after the first big chop. Now her hair is all even (before it was always this baby hair, some places are full, some are really thin, now it's all thick) so I will never cut it again unless she wants to.
I rarely use shampoo in her hair. Her hair feels really dry after I do (which convinced my husband to give up shampoo when he gives her her bath). I do conditioner wash, I put lots of conditioner in her hair and cleanse the scalp with my finger tips in circular motion. Her hair is very fine and really easy to detangle so I don't add extra conditioner to it, I just detangle really quick (I don't want the dirt to settle again on her scalp) and quickly wash out the conditioner and the dirt. When I'm done with her shower I dry her hair with a towel, add about a pea size conditioner to it and brush it with a denman brush to help the curls formation. Then I take a little bit (really a small dot in my palm) of olive oil or coconut oil and seal the moisture in her hair. And then we're done for two days or three days. I only freshen the curls with a dot of oil in my palm and rake through it the next day, if it's too frizzy then it's time for a cute little style, pig tales, pony tale and a flower, a braid or two in front, etc. anything will look cute on her at this age.
Basically I don't mess much with her hair, and I let it do its own thing. I just make sure we're using only healthy stuff (no silicones, no alcohols, only natural products) on her hair.
Your daughter's hair is even finer than my little one's. I think if you limit the use of the shampoo to only once or twice a month, you will see a big difference in her hair and I wouldn't worry much about some frizzy days. She's cute as a button so some flyways will not matter much.
A Mediterranean 3b lady
In love with my curls, love love love
CG since Nov/07

Co-Wash: VO5, Tresemme naturals, Fructis naturals
Cond: Nature's Gate conditioners
Stylers: Lotions made at home with coconut oil, honey, AVG, vegetable glycerin, OO, and EO.
Gel: LA Looks sports gel for high humidity days.

Hair goal: Waist length healthy curls