She can't really take the promise all that seriously, given that Hermione is far too familiar with the fact that men will often hurt themselves even if they try not to, and even then, they pretend that they hadn't really been all that hurt. She just hopes that Jamie isn't quite that stubborn, especially in light of the fact that he's actually injured at the moment.

So she watches him warily, tensing when he holds out his hand but still ready to jump in and do what she can to help him should he need saving. When nothing happens, she frowns a little in confusion, looking up at him as he begins to turn towards her. Then she jumps, startled, staggering a little at the sight of that strange beam of power despite the fact that it isn't exactly aimed at her. "Jamie!"

Despite her surprised outcry, things seem to calm down, and she stares from him to the dummy and back again with wide, bewildered eyes. "What was that?"