House of Hollow by Krystal Sutherland

A dark, twisty modern fairytale where three sisters discover they are not exactly all that they seem and evil things really do go bump in the night.
Iris Hollow and her two older sisters are unquestionably strange. Ever since they disappeared on a suburban street in Scotland as children only to return a month a later with no memory of what happened to them, odd, eerie occurrences seem to follow in their wake. And they're changing. First, their dark hair turned white. Then, their blue eyes slowly turned black. They have insatiable appetites yet never gain weight. People find them disturbingly intoxicating, unbearably beautiful, and inexplicably dangerous.
But now, ten years later, seventeen-year-old Iris Hollow is doing all she can to fit in and graduate high school on time—something her two famously glamourous globe-trotting older sisters, Grey and Vivi, never managed to do. But when Grey goes missing without a trace, leaving behind bizarre clues as to what...