Stuck on Paper

Rowan O'delle is a hopeless romantic with a treehouse in her backyard.
The treehouse has stairs on both sides of the fence leading to her neighbor's backyard.
Her neighbor Jeremiah Huxley shared it with her brother Rustyn when they were little.
Rustyn stopped going up there when he was 14, but Jeremiah needed a place to think, so he kept going up.
Rowan started going up there when her brother stopped.
Jeremiah and Rowan have been sharing a journal and talking to each other for years, however, they somehow never go up there at the same time.
Jace Caniro is close friends with Rowan and has been in love with her since he met her.
He is relentless and is her number one fan.
What will happen when Rowan has to face them both?