Girl goes birdwatching with a celeb and becomes her friend

So the girl injured her leg and can't join her friends on their trip. She's really into photography and does journaling. One day, while she's at her mom's café, a celeb spots her journal and takes interest, and invites her to go birdwatching with her and her grandma. They become friends. Girl intros the celeb to a bunch of normal teenage stuff. One day, while she's being dropped off from birdwatching, paparazzi swarm the car and harass her and she gets stressed and yells that she's not friends with the celeb. Celeb overhears and misunderstanding ensues, then usual book stuff and they become friends again. I've been searching this book for forever and remembered I had reddit loll