The physical shock from a moderately fast bullet expending in very close proximity to the spine "stunned" the central nervous system enough to disrupt and signals getting from her brain to her body. Ever play football and get a "stinger" in your shoulder? No permanent damage, but you can't move your arm for several minutes.

"Life is not a journey to the grave with the intention of arriving safely in a well preserved body, but rather to skid in broadside, used up, worn out, bottle of Jim Beam in one hand and a .45 in the other, loudly proclaiming WOW-- What a Ride!"