Is Katie exposed in sudsy new novel?

Is Hollywood Car Wash — the new novel about a young TV star from the Midwest who enters into a "contracted relationship" — about Katie Holmes?
Author Lori Culwell gave the typical nonanswer: "I do know someone who knows her right now and might have given her the book.. I can’t discuss any relationship with Katie Holmes, but I am sorry that she’s upset about the book."
On her lawyer’s advice, Culwell wouldn’t tell TMZ whether or not she knows Holmes, but she does maintain the book is "all based on real stories," and that "the main character is based on a person that is never, ever going to talk to me again."
The plot? A girl who lands a TV pilot and is forced to lose weight and completely change her appearance to be more marketable — including "new teeth, blonder hair, and a megastar boyfriend with a big secret." Does this mean we’re finally going to uncover whether Tom wears a girdle?