I think it helps to be organized, at least having an idea of what to write on a given day. I'm mostly a pantser--writing by the seat of my pants--but I like to have a loose outline. Sketching characters in advance is key for me. Also, the book "On Writing" by Stephen King is the best resource I've found to tackle the writing process.
I would tell her to keep reading, learning, exploring and that her writing will become more interesting. I'd also want her to know that one day she'd find the time to pursue her dream of writing novels. A person is never to old!
Before I could spell I told stories LOL. I have never been a great student in math or science, but writing and English came naturally to me. I even taught high school English and Journalism for a few years. I was a reporter before that, and worked in corporate communications the majority of my career--always writing. Creating a novel is an extension of those years.
I'm up there in years... so I write every day with the hope of publishing ten novels before I leave this earth. Hopefully, they will span a variety of subjects but always entertaining.