Every New Day (Heartland #9)
Amy is only 15, but she inherited countless responsibilities when her mother died. Most of all, she is expected to fill her mother's role as the horse healer at Heartland. Amy is talented, but still a novice. She can't admit she needs time to grow and understand.
When she can't cure Mercury, and she and Ty argue about his treatment, she decides to visit a Native American horseman who knew her mother. Amy takes Mercury to the mountain-top stable searching for answers, but she ultimately learns that she can't always chase down solutions. Sometimes she has to wait for them to find her.