Hedgehogs are great pets! I had one when I was little, and I currently have one that I got as a gift almost a year ago. They are very easy to take care of, and generally don't have a lot of health problems as long as they're taken care of properly. They are noctural, however, if they are handled frequently enough they don't mind being messed with during the day. She should definitely be sure that a hedgehog is what she wants, though, and be prepared to spend a lot of time with it, consistantly. Hedgehogs that aren't handled very often are very unfriendly and will puff their spikes out every time you try to touch them. In addition, know that the spikes definitely hurt when they puff out! They very seldom draw blood, but it feels like hundreds of needles poking you at the same time. Eventually you get kind of used to it, honestly, and it doesn't hurt as much.
They don't require a ton of space, and they're perfectly fine being solo, no buddy needed. Carefresh is the best bedding to use, which isn't all that expensive, and they eat high quality cat food, which my 15 lb bag I started with still has a good 5 lbs left! Mealworms and veggies as treats are always good, too.
Overall, really good pets, just be prepared to put in a lot of socializing time, and know that they are not little cuddly pets!