As her arm connected with nothing but air, Jean knew her attack had whiffed over his head. The sight of Greystoke's head sinking downwards was another indication that she had failed, how unfortunate that he was crouching lower, she didn't have the ability to do this when he was upright. The swing of her left arm ceased just above his shoulder, her arm relaxing just slightly. Jean's right foot sank into the ground a bit as she tensed her leg, her left leg lifted upwards with as much speed as she could muster. 

The blade began to rip its away across her lungs, shredding her left lung. It snagged on her ribs, breaking them even further, beginning to fill her lung with blood. It spasmed and pain became visible on Jean's furied visage. But instead of letting herself succumb to this pain she clenched her teeth so tightly that her right incisor cracked from the pressure, she refused to cease her attack.

Greystoke's constant dodging would work against him in this situation, as he dropped downwards she too dropped her arm. Not with intent to strike, but intent to box in. Her left leg rose upwards in a vicious knee strike, aimed towards his chin as he crouched lower. With her arm above his shoulders, and her knee coming up towards his chin. He would be forced to find an escape or his head would pop off his shoulders like the cork from a champagne bottle. With her knee being just a deadly a weapon as her hands, this knee strike to his jaw carried more than enough force to kill normal men with a single strike. This knee carries enough force to derail a train, this knee carries enough force to tear Bull Elephants in half. 

Should this connect with Greystoke, well, we'll see how tough he is.