Whitney credited her longevity to a healthy lifestyle, in which she banished sugar and consumed 86 vitamins and minerals a day.

The Los Angeles Times said Whitney's "Thunder Heights" is considered the first of the modern paperback Gothic romances.

"I wish I could think of a suitable name for the kind of writing I do," she said in a 1981 piece she penned for the Mystery Writers of America. "We're read by millions ... yet we've never become quite -- legitimate. 'Gothic' doesn't do it -- too restrictive. ... 'Romantic suspense' sounds terribly sappy. Though we may have to accept that term for want of a better."

Throughout her career, Whitney authored 39 suspense yarns for adults, 20 juvenile mysteries and 14 books for children, which combined, sold millions of copies, the Times noted.

The Mystery Writers of America bestowed its coveted Grand Master Award for lifetime achievement upon her in 1988.

Whitney is survived by her daughter, Georgia Pearson; two grandchildren and two great-grandchildren.