She stiffens slightly and, before she can stop herself, snaps "Try telling that to someone who didn't spend their life with the threat of 'final dispensation' hanging over their head."

Her eyes widen slightly, and her hand goes toward her mouth, as though she can catch those words, or at least prevent more from escaping. "I'm sorry-I should go." And, unless Donna moves to stop her, she's gonna get up and not precisely run but move very briskly for the door.