hi, NUgirl. yes, the MCAT is a little low, but your GPA is very solid, especially coming out of northwestern. i graduated from NU as well a while back but my science GPA was nowhere near a 3.58 and i've gotten in. your exact chances will depend on a lot of things (e.g. state of residency matters a lot) but my experience is that it is well-understood how intense the pre-med curriculum at NU is, and it pays off in the end. having said this, i would still retake the MCAT--the 25 will be what keeps you out of some schools. aim for something 30ish. assuming the extracurriculars are in order, you'll be fine.
good luck to you!