Jack gives a startled yip as he's swung up into her arms, but his arms go around her neck in automatic response to keep him in place, just in case. Also keeps them from flailing around and getting in her way as she jumps. It's rather like being scooped up by Ted, except Ted is heavier and his bark-skin is much harder and also Ted has more handholds. Also, Ted has an unpleasant tendency to go for him around the waist and just hauling him about like a sack of potatoes. This is, arguably, better.

Once he's on his feet again he shakes himself, a little doglike, and gives a sheepish grin, back. "Easy," he agrees. "Thank you. You really are very strong! I wasn't sure just how far that went."