From the Snow Queen's Laugh

Both Tinker Bell and Periwinkle are born from Elsa's first laugh. The fairy twins become stranded in an unexpected blizzard when the fairies are bringing Winter to the mainland. Young Elsa and Anna are also lost in the woods, stuck in the storm Elsa made. The two groups cross, and must help each other if they want to escape the woods, but certain dangers don't make it an easy task.