A fall from even a very short distance can result in injury depending on how they land. Obvious injuries are broken bones and sprains. Internal injury is often not obvious initially. What her closely for the next week or two and keep close track of her food intake (count kibble), activity and urine and feces colour and texture. If anything seems out of the ordinary, get her to the vet. Most of the time they are fine after a fall but not always.
It is said that in the wild they roll into a quilly ball which cushions the fall but most of our pet hedgehogs have not read that book. When they fall they don't even think of going into a ball and usually land splat on the floor.
I don't want to scare you, but about a year ago, one member on the old CnQ forum suspected that his hedgie had fallen from a desk. The hedgie seemed "all right" and the OP couldn't find any "injury". Then the hedgie became lethargic and showed similar symptoms to attempted hibernation. Other members warned the OP about the possibility of an internal injury and urged him to take the hedgie to the vet ASAP. He didn't take the warning seriously and assumed his hedgie was suffering from wheeling exhaustion instead.:evil:
The poor hedgie died shortly after, most likely from internal bleeding.
As Nancy pointed out, many of our domesticated hedgehogs seem to have forgotten how to ball up and protect themselves from injuries when they take a fall. I've heard of some hedgies sustaining severe injuries from falling a mere several inches. All depending on how they have landed.
Probably your hedgie is okay, but please watch her closely in the next several days as advised.