The June Carter character exemplified committed action in the service of a value that was dear to her. The value I would identify (not verbalized by her in the film), would be something like 'Marriage as a committed friendship' or 'Building intimacy'. Some of the elements of committed action on her part included remaining Johnny's friend when he was at his least likeable, rejecting his excessive and self-destructive behaviors while continuing to love him, even remarrying when she couldn't have Johnny. Mind you, he also exemplified similar committed action in continuing to ask her to marry him despite repeatedly being blocked in achieving the desired outcome :).
ACT Principle: Outcome is the Process through which Process Becomes the Outcome