Looking for a book for my friend

Hello! I'm looking for a book that my friend might like.

I know she likes vampires and gothic atmospheres, she's a very big fan of Dracula (the film that came out last year), Frankenstein (yep the new film) and Twilight. Those are her vibes. The issue is that every time that she has recently tried to read something, she ended up DNFing it because the writing and story were too juvenile for her, she's looking for a more mature approach of things, a book written by adults for adults. Not necessarily explicit, more like mature. I put the "horror" tag because of the themes mentioned, but anything would work.

Thanks!