To me, this is part of the disconnect between what the writers want her to be, and what she really is.

WORD. i've been trying to put into words just why gwen cooper annoys me so much (rose tyler annoys me for the same reason) and you've just done it more succinctly than i ever could. not only do they both come across as terrible teacher's pets; it's monumentally lazy writing. don't go around having everyone else say how wonderful and brilliant and competent your pet character is; do the friggin work and actually make them wonderful and brilliant and competent.