Window Bird

Two little birds were perched by a window
Watching as time slipped by.
One little bird grew tired of spectating,
And quickly learned how to fly.

The other little bird was deep in slumber.
And didn't hear her sister's good-bye.
Instead, found herself looking out that same window
Stuck on the other side.

After Charlotte's older sister, Nora, runs away from home, Charlotte struggles with the absence of her sister and the shield she provided from their mother's obsession to keep her daughter's schedule constantly busy in order to keep up with appearance in the community. The same day Charlotte and her parents found a crumpled note where Nora should have been laying, their fence was vandalized with a spray painted bird.
As Charlotte attempts to maintain her sister's upright reputation, she starts to discover the same drawn out birds at different spots in their community. With the help of a few friends and a boy named Advay with heterochromia eyes and zero concept of time, Charlotte attempts to locate each bird in hopes that it'll lead her back to her sister.
Are the birds a secret cookie crumb trail to Nora or just pure coincidence? What will become of the birds?