HAUNTED SEASONS by Debra Easterling

Spring Wyatt was only nine-years-old when she watched them all die. Now, eighteen years later, she can’t imagine how her grandfather, could manage to die twice. He leaves her not only his vast legacy, but also the custody of her twin-sister, Autumn, a special-minded girl that supposedly perished the day their parents were murdered. Totally confused, and rightfully angry, as to why she had been kept separated from her only remaining relatives, Spring sets about investigating the Wyatt family mysteries, in the process discovering that she has strange abilities she never knew she had, abilities that only exist when she is near Autumn. The danger is Spring's abilities magnify when angry, and she is ALWAYS angry.