That fleeting moment is all Rey needs to gauge the situation. Both in regards to Sato and the 'children'. While he doesn't seem to be flawlessly coming up on top, he seems far from discouraged judging by that look on his face.

With two of the gray things coming to join the fray, she grabs for her knife again, arching back to avoid the needles from the Lady's lashing arms. One hand seizes its bony wrist, its startling strength nearly overpowering even Rey before driving the blade of her combat knife through its inner elbow. Between the force and the impact of the joint, this attempt has more success than her last.

Having lost mobility in one limb, Rey makes to twist the other before releasing the knife. Metal or bone or whatever it is that makes up this thing cracks and breaks. Still, it doesn't scream or wail from behind that metal mask.

Leg sliding over its good arm, the right one comes clean off. No blood. No gore. Like taking apart a plastic toy.

Shit. It's almost disappointing.

Until she uses the severed arm to stab its needle fingers through the skull of the closest 'child' moving towards her.