IMO the iPad is a toy. It's great for apps, watching movies & TV shows, basic internet use (surfing the web, email, facebook, etc). Just things you'd do while playing around or in your free time.
However, I would never use it for school/work projects where you would need to research, write a paper or anything else that would be time intensive. It's difficult to cut & paste on, the screen isn't as big as a computer/laptop and can cause eyestrain when typing on it for long periods of time, and it's not as easy to toggle between the internet screen, word program app etc.
With all that said, I'd think about what items you have in the house and what she'd spend more time using it for. For example, we just bought our 8 year old an iPad 2 for Christmas because we have a desktop and 2 laptops he can use when the need arises for school papers or the odd flash website that can't be seen on the iPad. But he was always on my iPad playing games, doing the reading apps, taking videos of himself, etc. So, in my mind, he's going to get more use out of the iPad, than he would out of a laptop and he has access to a computer when needed, so we went with what he would use most. But if I was buying something for a college student to keep in their dorm room who has no other easy access to a computer, I'd go for the laptop, as they're going to get more use out of that.