I know this topic is very subjective so just looking for some opinions. Yale says that someone with regional or national awards, which I have, can send a supplement, and my guidance counselor thinks that I should, but I feel that my awards and my writing ECs will kind of speak to my talent/involvement more than an admissions officer reading my work. Any thoughts on this? I appreciate any help 
One of my D’s won a national writing award. She listed the award and then included a link to her essay which had been published. Can you do something like that?
As you are applying with regional and national writing awards, your essays will be given more scrutiny, as Admissions Officers will expect them to be better written and more nuanced because of your awards. How secure do you feel about your essays? If you have any doubt or hesitation whatsoever, then I would submit a piece that has won you an award and call it your writing supplement. And if your GC is suggesting you send in the supplement, I would trust their judgement!