My 9 y/o daughter has hair almost exactly like your daughter's. She hates it, too. She doesn't get teased at all, though. She gets compliments on her hair constantly, but I think she does not like the attention her "big poofy hair" brings her. I'm hoping to someday get her to wear her hair down again, but it's been years since she has. I am here today to look for help with products, too.
I wish you luck and I wish I had some advice. For now, I'm in the same boat (minus the teasing - and I'm disgusted that it is happening to your child).
my hair was like that!!! im a bit older now and im in an all girls school and i always thought my hair was too puffy but its gown and its straightened out a bit when i was a kid it was a four now its just a 3C because the weight of it straightens it out!! but wait a few years she will love i i hated mine for so long i was going to shave my head or get it permanently straightened but im 13 now and now my friends tell me my hairs nice too and not just adults!! when i was younger i wouldnt like washing my hair cause it hurt to much when i brushed it but i learned to wash it everyday and use TONS of conditioner!!! even just do this for a while and it might help also dont brush it when its dry or starting to dry!! and maybe use a leave in conditioner or a mouse!!! hope this helped