I agree with Simon.
If she were a painter, or sculptor and her work won her national acclaim; would her work also be considered 'public domain'?
Just because you win something, doesn't mean that you 'owe' anyone anything. If I win a math contest; I don't owe you a homework assignment. If I win a programming contest, I don't forfeit my software I've written over the years. Why should she be blackmailed (and going national like this is nothing short of blackmail) into giving a very successful TV franchise rights to her personal property?