Quote 1
Peter turned at once to Lucy.
"I apologise for not believing you," he said, "I'm sorry. Will you shake hands?"
"Of course," said Lucy, and did. (6.12-14)
Peter may seem high-and-mighty sometimes, but he is always willing to admit when he is wrong. As with Mr. Tumnus, Lucy is ready to forgive him right away. Unlike Edmund, she doesn't hold grudges.
Quote 2
"It was all Edmund's doing, Aslan," Peter was saying. "We'd have been beaten if it hadn't been for him. The Witch was turning our troops into stone right and left. But nothing would stop him. He fought his way through three ogres to where she was just turning one of your leopards into a statue. And when he reached her he had the sense to bring his sword smashing down on her wand instead of trying to go for her directly and simply getting made a statue himself for his pains." (17.2)
Once redeemed, Edmund demonstrates great courage and disregard for his personal safety.
Quote 3
"Madam," said King Peter, "therein I pray thee to have me excused. For never since we four were Kings and Queens in Narnia have we set our hands to any high matter, as battles, quests, feats of arms, acts of justice, and the like, and then given over; but always what we have taken in hand, the same we have achieved." (17.35)
At the end of the book, Peter, Susan, and Edmund are still willing to take on new adventures, and Susan is still the voice of conservative moderation urging them to avoid the unknown.