Scattered Leaves by Virginia Andrews
After tragedy tears her family apart, Jordan March is shipped off by her domineering Grandmother Emma to live with Emma's long-forgotten sister. Shuttered in a rundown farmhouse, Aunt Frances is the strangest person Jordan has ever met. Why has Grandmother hidden away this fragile, harmless woman? Did Frances grow up much too fast, like Jordan did? In the shadows of the farmhouse, Jordan is about to unearth the shattering truth - with terrible and far-reaching repercussions for the March family.