She might've made it all up but her message isn't wrong. Everyone makes mistakes, however mistakes do not mean failure - giving up means failure. Success comes from learning from previous mistakes and improving upon them or not making the same mistake twice.
It is true, though. A lot of authors DO go through a ton of flops before hitting a best seller. Hell, even ESTABLISHED authors turn out stinkers from time to time. Art is an organic process of learning, revising, and going with your gut even when everybody tells you it's wrong. If it were easy, literally ANYBODY could do it.