Definitely not. 'Girl in the Bunker' is purely a work of fiction. The creators crafted the story from their imagination to offer a thrilling and unique experience to viewers.
I'm not aware of any specific book or movie with this exact title. However, there are many stories about people in bunkers in general in various forms of media. So it's possible that there could be something similar out there that might be related in terms of the concept.
I'm not sure. It might have some roots in truth, but it could also be a creation of the author's imagination. We don't have enough information to know for certain.