Even if your daughter - for whatever reason - does not get any sort of job (and I think it would be good if she possibly could) , there is an awful lot that she can do at home/working part-time at anything to improve her prospects.
As *thing has said, she should learn how to use the standard software found throughout media industries (eg InDesign and Photoshop and Excel).
She should look at online courses for writers and editors - there are lots - this is just a random example: write-mentor.com/
She should also look at websites run by various writer's groups/by certain authors. This blog - it's old, but the site is secure - has an absolutely brilliant glossary of publishing terms: www.stroppyauthor.com/p/how-to-speak-publisher.html
There will be more useful info out there on other writer's/editor's blogs.
She should find out what's being published at the moment, and why. The Bookseller has already been mentioned. The online subscription is not cheap but it really is very, very useful. (Or read it at the local library perhaps, or a monthly trip to a nearby academic library, if they will give her access. Can she get a local library card that will let her read journals online?) If she is not doing so already, she should carefully study the Writers and Artist's Year Book (a worthwhile one-off purchase or again, try your nearest reference library).
She might also like to look at publishers' websites to see if she can spot trends etc and see the sort of written material that is used to promote and sell books. (As an exercise, she should try and write advert copy and back cover blurbs herself, for books that she already knows. You learn to be a better writer - of any kind - by constant practice....) She might also practice translating different genres of writing (adverts, science books, gardening/fashion, children's, cookery... into Spanish.
She should also find out what day or evening courses are available at, for example, the nearest FE college - or even commute one evening a week, if possible, to one run in London. Has she considered dong an MA? - there are dozens in creative writing or similar. They don't mostly lead to jobs or necessarily create better writers, but they will teach her a lot about media industries, and may give her some useful contacts. There are several different types of courses run by different London universities, which would at least put her on the spot.)
Can she join or even set up a local or online book club? That way, she will meet people interested in books and get into the habit of talking about them in a more objective way.
She should find out how publishing works as a business. It's a creative business, right enough, but if she ever gets a job she will find that budgets, cash flow, foreign rights deals and sales targets are all utterly essential. That's what editors spend an awful lot of their time thinking about. Most actual writing is done by freelancers, after all.
(And, just as an aside, you say she is working on 'her art'. If this means visual art, then, while it is useful for editors/sales people etc to be visually aware and appreciative, being a book or media designer is a totally different career, usually requiring art school training. Almost all illustrators are freelances, and most writers don't design or illustate their own books.)
As others have said, she should write as much as she can - a blog or posts on any sort of social media. Also send articles to the local newspaper or free community magazines. Read the blogs written by other would-be writers, to see what they are learning and to find out who she might be comepting with for jobs.
See if she can volunteer, even if just for half a day a week, in a school or charity or church or a big local company to see how books/written media/information or promotional material are used in that particular environment. Even just spending days hanging out and observing in a good local bookshop would be helpful (with the manager's permission, of course).
Similarly, just spending time in local libraries seeing the sort of books that are on display can be instructive. All this can be put down as 'research' on her CV.
I apologise if your daughter is doing all this already,
And I agree with previous posters who say that editorial/copywriting jobs for inexperienced graduates are like hen's teeth. But ANY job in publishing - even as an office junior - is worth getting. Once she has a foot in the door, there are several professional development courses available, and anyway, she will be learning on the job.....
Best of luck.