The Butterfly House by Marcia Preston
As a child, Bobbie Lee found refuge from her lonely life at her best friend's house. Rockhaven was a place of magic, colored by the butterflies that Cincy Jaines's mother, Lenora, studied. Her friendship with Cincy and Lenora soon became Bobbie's compass. But the tangled intimacies between them began to unravel, and in one night, Rockhaven became a place of unspeakable tragedy.
Now, a decade later, the long shadows of that night continue to haunt Bobbie, despite her attempts to hide from the past. When a stranger with ties to Lenora and Cincy arrives at her doorstep, she is forced to confront the memories she has tried to avoid, and the dark secret at the heart of the tragedy slowly emerges.