After a few rounds, you can start fighting back. If you want (to get a feel for the battle mechanic), you can go ahead and click on an attack point (there's only one at the moment) to attack her and eventually defeat her that way, but isn't that a little boring :P. If you mess up and defeat her anyways, don't sweat it - you'll see her again, and you can always go to the recollection screen (mentioned below) to fight this same instance again.