Does Stephen King use ghost writers?

No Lily. Stephen King does not use ghost writers. As a matter of fact, at one point in time, he was writing so prolifically (a lot) that he published under the pseudonym (fake name) of Richard Bachmann because he was afraid of saturating (overwhelming) the book market.

Sometimes writers have a very creative spurt and can keep writing and writing. Other times, they hit what is commonly referred to as "writers block" where they have a hard time getting their ideas on paper or finding an idea. Sometimes, there is a lot of research that needs to be done, or they spend time building the characters and their environment. Both of those things, among other personal or professional reasons, can slow down the time it takes to write and publish a book.

My suggestion to you would be to ask your friend to tell you exactly where she received her information. If she cannot tell you or it was a rumor she heard, that is not considered to be a basis for a "well known fact." Well known facts are something that we can prove. Instead of driving yourself crazy trying to disprove her, you should make her prove that what she is telling you is true. She is the one who came up with this.

If she can't prove where she received her information from, than you can tell her that until she does, she is only spreading gossip and rumors.

I hope this helps.