How can I convince my sister not to become a photographer?

[Jeannie]

Educate her as to what good photography is and have her compare her images to those of real pros. Go buy a few high end magazines that reflect her interests (babies, ponies, yada) - point out the differences between her photos and the professional ones. Encourage her to actually learn photography - the technical requirements, composition, and talk to her about the fact she is no where near ready to start a business (oh thank you!) but is only beginning to learn the subtle and difficult discipline of photography.

With teenagers, once they find out how hard photography actually is, they often wander off somewhere else.