1. What if Jack Frost was a friend of Elsa's while she was locked in her room?

2. What if Jack Frost was a friend of Elsa's before he was chosen?

3. What if Elsa was able to see Jack her whole life, but never told anyone in fear of being labeled as crazy?

4. What if Jack had grownup as a servant for the king and queen of Arendel?

Different possibilities all ending with the same thing. Jelsa.

Let me know which one you like best and I'll try to write it.