All the help from you guys helps me getting Vaylin down to about 60 - 50%. After that it does not matter what I do, she always gets me. She does something and my character cannot run or move. By the time it can move again I'm so far down on health that I cannot make it to any healing circle. No, I'm not stunned or similar - after a few times hitting jump I suddenly can move again, but its way too late.
As a trooper I must say this is near impossible if not impossible to win.