Petko´s movement is still not good, but at least there is a little more bite on her shots.
It's all to do with confidence. The more she plays and doesn't injure herself and gets used to it, the better and more confident she will feel about everything to do with her game - movement, shots etc.
I just hope that Petkovic's movement is a mental problem, i.e. she doesn't trust her ankle yet. She has huge problems pushing off the right foot.
I'm sure it is (see my post above yours). I still think she's frightened to move without thinking/worrying about it. Her ankle is still most probably very weak and she's worried about going over on it again.