It was difficult stalling her long enough until Thorax was certain Handy had managed to sneak in. Not being able to sense him and still being able to sense a great many other ponies in the nearby vicinity did wonders for her nerves, as you could imagine.  It was like taking a youngling on their first outing to learn how to feed on their own, only you had no idea where the kid went, the kid hated you, and the target was particularly dangerous. Oh, and to make things better, the kid may or may not accidentally kill the target and you had to hang around to ensure that didn’t happen.