Illustration future?

I have a friend who took a course about illustration children's books. Her idea itself wasn't exactly....kid oriented, but she did some fantastic illustrations. Being a children's book illustrator is quite a good business actually. My friend, who is an illustration major, has said that she would love to do book illustrations, and that there is a big market for them. Personally, I don't know how much I would enjoy drawing for kids, since my humour is a bit more...adult, I suppose. But if the story's good, I'll do it.