Oh this is so fun!! I'm intrigued by your book, I have to say - love a Welsh setting! Mine is set in Norway and it's a spooky one. I love your outfit - especially the fairy crown!
I think I'd wear something a bit Anne Rice, but not full on. Maybe a nice dark dress with a corset and a low back. Some velvet and lace. A little Victorian, I'd say, but perhaps more "fantasy Victorian" so the dress is more chemise style than full on full petticoats and hoops.
I've got a short French bob but I'd pull a bit back at the front into twists, and find an antique style clasp. Some little lace up boots with heels.
You've got me excited now, I'm off to Google real versions. 😂