The leg around her throat wasn't what Kate was expecting and she's caught for a moment, long enough to cut off her air and knock her onto her back before she pulls free, punching Johanna hard in the thigh, knuckles angled to dig in and bruise.

She scrambles to get her bearings again and then twists to re-engage, putting herself immediately into danger again, coming from an angle and aiming to grapple a hold on Johanna's legs. She's clearly working for a leg bar, trying to pull the limb straight, foot up to her ear while her own legs push Johanna's body the other way, threatening to hyperextend the knee if she can pull it off. If she can't, well. More strangling it is.