How do you use severely in a sentence?

The straight-backed posture, the sensible walking shoes, the plain dress with its high collar and sleeves straight to the wrist, the narrow-lensed glasses perched at the end of the nose, the lack of jewelry and make-up, and the hair pulled tightly back into a no-nonsense bun all combined to give the young schoolteacher a severe, almost forbidding look to her normally rambunctious students.