My older daughter has curly hair, and I started using "real" shampoo and conditioner on her at about that age. Obviously you have to be careful about not getting it in her eyes, but it is well worth the extra effort. Our favorites are Aveda Be Curly, and Aveda Dry Remedy (since her hair is also very dry). I leave the conditioner in for a while while she's in the bath, and after it has soaked in a while, I brush her hair using a wide-toothed comb, starting from the bottom and working my way up. And then as soon as she gets out, I squeeze as much water as possible from her hair and immediately put on an anti-frizz serum. This all seems to keep her hair from getting tangled and frizzy.
As far as brushing her teeth, Sonicare makes a kids' toothbrush now. It's not cheap (around $60, I think), but it will last forever (just get new brush heads every 6 months or so, and the brush heads are around $10 each), and does a GREAT job of cleaning their teeth! It tickles a little bit but both of my girls love it, and it makes dentist visits very easy since they have no plaque to speak of. Also if they insist (as my younger one does) on brushing their own teeth, the toothbrush does a great job of cleaning even when kids wouldn't do so well on their own.
I hope that helps!