If someone is training to become a janitor and they have excellent marketing skills, it would not be rude to say he/she/it should not be a janitor and should be a marketer instead. You are trying so desperately to be offended by something that doesn't have to be offensive.
I don't think her ability to get her work known would translate well to getting other people's creations known. Anyway, everyone ought to know how to market themselves, or suffer at the whims of those who do.
But I think she's likely already demonstrated enough to land a junior front-end gig somewhere. Along with a work ethic and learning ability, she'll produce in that role.
If someone is better at x than y, it doesn't mean they are bad at x, especially if they are very good at y.