Yes.  The pencil trick is a good example of the vulgar magic she is capable of.  The "light as a feather; stiff as a board" is a bit much for now.  Other good example though ... levitating a petal, pushing a sheet of paper off a desk.  

What Diane does is more sheer power, but is coincidental.  That is .. the guy happened to overthrow.  The teacher walked by at the exact right time.  Even Diane would have a hard time buying magic as the cause - even though she saw the events before they happened like dominoes lined up.  In her mind she thinks, "Couldn't you all see it unfolding?"  (Heaven help anyone who tries to hurt her laptop.  She started with a high end gaming laptop and customized that.)  HOWEVER, Diane couldn't pull off the pencil trick because she doesn't believe she could.