Not feeling the least bit guilty for slapping his hand (actually, slapping the Doctor, in general, is something Morgana will probably never feel guilty about), she says nothing about bickering. It is sensible to stop, but that does not mean she has to give him the satisfaction of agreeing with him.

So, what he gets is Morgana following along in relative silence. Every once in a while, she surreptitiously shakes her might-be-a-screwdriver, hoping to dislodge some water (perhaps it hit a rock on the way down, she doesn't know and she's not going to ask) to get it working again.

When she isn't fiddling with her broken gift, she's pulling her soaked skirts away from her. They're sticking to her and making it a little more difficult to move as freely as she'd like.

His current idea is also sensible, but, yet again, that does mean she has to tell him.