Jareth was held captive by Carter for the school year. Leona used her newfound powers to defeat Carter and get him expelled, and on a trial for an Azkaban sentence. In the process of strengthening her skills, Remus and Leona called their relationship off because they didn't want to hurt each other. They remained friends. Sirius and Jareth remain lovers. James is now more protective of Jareth than ever. The groups' friendship continues to go strong.
In the future, Lily and James marry and Lily becomes pregnant with a son. Remus and Leona decide to try again, now that they're stronger. Jareth and Sirius live together as a couple. They plan to marry when it becomes legal.
When the boy was born, the family of friends was filled with more love and joy and they grew closer than they've ever been. Little did they know, the war would continue and their futures were bleaker than could be imagined.