Alex Asked: Does anyone know the name of this book?

I remember reading a book by Lois Duncan, but I cannot remember the title of the fictional book. I do, however, remember the plot of the book. I remember it was about this girl who had psychic abilities. She could see things to come, and she would have feelings about certain people. But the only real thing that stands out about the plot of the book, was that she had to use her psychic abilities to find and save her brother. I guess he had gotten stuck out on a mound of rocks at the beach. He lost track of time, as the tide started to come in, and it trapped him on the island of rocks. So she had to use her abilities to find him and save him before he drowned. Well, hopefully this will be enough for u guys to go on….If someone does know the name of the title of the Lois Duncan book I'm talking about, could u please give it to me….Thx in advance….;)