She's incredibly well spoken, and the documentary does a nice job of showing a vast number of influences on her life, from her conservative, Republican parents (who are amazing at respecting their daughter's beliefs, even though they are often polar opposites from theirs), conversations with abstience only advocate and minister Ed Ainsworth, who Knox took the True Love Waits abstinence till marriage pledge with, various teens in the community, local politicians, etc.
I'm impressed as a teen that she's able to have conversations with Ainsworth about abstinence only and homosexuality as a sin. Knox ends up advocating for some students trying to start a gay-straight alliance at their school, as she concludes that abstinence only does not address the educational needs of same-sex couples. Fred Phelps and Westboro Baptist make an appearance as well.
The impressive part to me is that the movie shows how she is genuinely trying to reconcile her personal beliefs with the religious' teachings saying homosexuality is wrong, and when she has conversations with Ainsworth on either topic, she always maintains her composure, no matter how much she may agree or disagree with his message.
Even if you may not agree with her positions, the movie is excellent at showing how youth can, and do, get involved in their communities.