I'm trying to remember the name of a book I loved when I was a kid. It was set in a castle, with the main character named Jenny, twins named Malcolm and ? and a cousin who acted like a jester ( i think his name was wit?). The twins are actually triplets and the 3rd brother is crazy and haunts the main character. Any ideas?
The book you're describing is Silent Stalker by Richie Tankersley Cusick
"Before Jenny Logan even entered the forbidding castle-a replica of the Worthington's ancestral home in England-a terrified stranger warned her away. Was the warning real-or just another example of the family's macabre sense of humor? Jenny couldn't be sure. She only knew her summer vacation with her father suddenly became a nightmare when predatory Sir John Worthington invited them to stay-and his grandsons, the gorgeous Malcolm, his twin Derrick, and their mischievous cousin Wit spun a web of intrigue, romance, and deceit around her. She's forced to play by their rules now, and battle the castle's ancient curse, which decrees that she will go mad, or die...or simply disappear...."