On one hand she can learn how hard it can be to make money from photography, perhaps dissuade her from any romantic dreams of being a paid photographer, a reality check. On the other hand you don't want kids to fail too much. You want them to have goals that are just within their scope of achieving and to achieve those goals. These small increments of confidence building and boundary expansion last a lifetime.
Let's be real the business side of it is tough no matter what. There are things that I never thought about when I was young like legal release forms, taxes, copyright, etc.
I think if you break the business side of down to small parts as goals, she will come out of it okay, even if she doesn't make any money. You can't help her too much, you can't take over certain parts of it for her. She will either push through the tough stuff like the legal release/permission forms (as an example) or realize the business side of it isn't for her.
I think achieving all the small goals will be a net positive and she will learn a lot, even if there's a lot of disappointment at the sales end of it.
