(written from a Production point of view)
Hennessy has doubled for stars such as Tea Leoni, Demi Moore, Jennifer Tung, Leelee Sobieski, Lucy Liu, Mena Suvari, Piper Perabo, and Helen Mirren. In 2007 she was nominated for a Taurus World Stunt Award for best specialty stunt in the film The Guardian with fellow stuntman Tanner Gill.
Hennessy was taught the use of a trampoline and other sport activities like a motorcycle by her father. She became a professional athlete, earned several prices and awards and is honored in the Worlds Acrobatics Society Legends Hall of Fame and the USA Gymnastics Hall of Fame. Hennessy is also mentioned in the Guinness Book of Records (for her trampoline work) and holds the record for the highest fall by a stuntwoman, for a scene in Charlie's Angels, where she doubled Lucy Liu, but the scene was cut from the aired movie.
Among her stunt resume are films such as Bad Boys (1995), G.I. Jane (1997), Deep Impact (1998, with James Cromwell, Denise Crosby, Gary Werntz, Mark Moses, Concetta Tomei, Ellen Bry, Tucker Smallwood, Kurtwood Smith, Christopher Darga, Mic Rodgers, and stunts by Tom Morga, Brian Avery, Joni Avery, and Denney Pierce), The 13th Warrior (1999), Teaching Mrs. Tingle (1999), What Lies Beneath (2001), Planet of the Apes (2001, with Cary-Hiroyuki Tagawa, David Warner, Erick Avari, Eileen Weisinger, and Kevin Grevioux), Clockstoppers (2002, directed by Jonathan Frakes, and with Ken Jenkins, Gina Hecht, Billy Mayo, Jenette Goldstein, and stunts by Brian Avery, Joni Avery, Rick Avery, Joey Box, Phil Chong, Kevin Derr, Buck McDancer, Gail Monian, and Justin Sundquist), The Scorpion King (2002), Charlie's Angels: Full Throttle (2003), Surviving Christmas (2004), Poseidon (2006), The Guardian (2006), and She Lived (2008).
Hennessy has also performed stunts in television series such as The Chronicle (2001), Six Feet Under, Buffy the Vampire Slayer, The Shield, Cold Case, Crossing Jordan, Passions, Jericho, CSI: Crime Scene Investigation (2006, with Wallace Langham, Liz Vassey, and Nancy Youngblut), True Blood (2007), and Life (2007, with stunts by Manny Perry).