The End of the Rainbow (#4) by V.C. Andrews

Rain's precious daughter, Summer, is about to turn sixteen. Her future lies wide open before her and she carries her mother's wise advice close to her heart: life is hardship, but above all, life is hope. Like all girls her age, Summer dreams of growing up a d making her own life, of falling in love and finding her soul mate.

But a devastating tragedy will force Summer to stare into the cold eyes of adulthood long before she is ready. She will learn very quickly about hardship- but what of hope? Is she as strong as her courageous mother? Or will she crumble? 

All her life, Summer has lived on the Virginia estate where the Hudson family's  secrets have lurked among the shadows for generations. Now it is time for Summer to discover secrets of her own. Some she will keep. Some she will share. SOme will force her to flee the only place she has ever called home. And some will haunt her for the rest of her life...