I'm a freelance web designer, too!
I work full time at a graphic and web development firm, but freelance on the side doing web design and front-end web development. I also offer web hosting and related services. I don't do programming myself, but sub-contract that type of work whenever necessary.
With freelancing, you're also able to take on more challenging jobs and turn them into learning experiences to help further your own skills, etc. Something that you don't always have the liberty to do when you're working for someone. Doing it on your own, you're able to decide - hey, I'm going to take this job and spend extra time on it learning some new technique (obviously you can't bill the client for your learning curve time - but it's great that you can make that decision for yourself).
GL to your friend! If it's something she does for her day job anyway, she's already got the skills and talent. It's a good way to make some extra money, especially if it's something you love to do!