When my mare was a filly she was slightly cow hocked. It bothered me. The old timers say run them on hilly pasture. So, I did. That effort, in fact, helped. One could argue it would have occured w maturity anyway - and that may be so. I also have a very strong suspicion my girl is part akhal teke, which is one breed where a "slight" amount is accepted and very common. I imagine as your girl matures and muscles it will improve.