Evony

Lia is an ordinary girl with an ordinary life.
Until her parents are killed in a car crash.
Lia is sent to her aunt and uncle's home in Minnesota, away from the few friends she had in her home in East St. Louis, and her being painfully shy wouldn't help. Her uncle, a well-known author who is failing to come up with new ideas, welcomes her, while her aunt, who is a surgeon, doesn't get to spend much time with her.
When Lia goes to school, no one speaks to her often, and her old friends have replaced her already. She makes no new friends, despite her hopes.
Until, she meets Evony.
Evony is not a person, she is a horse.

Horses can break people.
Horses can heal people.
Horses can change people.