(written from a Production point of view)
Grierson began her career in the early 1990s. She is credited as a sound editor on the 1992 independent film Deuve Coupe, starring Kieran Mulroney and Larry Hankin. She became an assistant director soon after, with one of her earliest credits being Second Second Assistant Director on a 1997 episode of the Showtime series Women: Stories of Passion featuring Nicholas Coster. She subsequently worked as Second Second Assistant Director on the 1998 drama films Starstruck, starring Spencer Garrett and Clarence Williams III and the 1999 films Let The Devil Wear Black (featuring Jonathan Banks, Martha Hackett, Tony Plana, Chris Sarandon), The Prince and the Surfer (starring Vincent Schiavelli). She was also as 2nd 2nd AD on the PAX Television anthology series, Chicken Soup for the Soul.
As a Second Assistant Director, her films include At Sachem Farm (featuring Jim Beaver and Keone Young) and Sonic Impact (starring Sam Anderson). After working as an Additional Second Assistant Director on the 2000 film More Dogs Than Bones (starring Louise Fletcher and Whoopi Goldberg), she became a 2nd AD on such films as Donnie Darko (starring Holmes Osborne), Jay and Silent Bob Strike Back (featuring Diedrich Bader), The Cooler (starring Paul Sorvino), Grind (featuring Christopher McDonald, Jennifer Morrison, and Stephen Root), and Shopgirl (featuring Clyde Kusatsu).
Grierson's only film credits as a First Assistant Director thus far are 2000's Everything Put Together (featuring Shelly Desai, Matt Malloy, and Alan Ruck) and 2004's Palindromes (featuring Richard Riehle). More recently, she was Second Assistant Director on such films as Tenacious D in The Pick of Destiny, Black Snake Moan, and One Missed Call (starring Ray Wise) and the Second Unit Second Assistant Director for the hit comedy film Knocked Up. She recently completed work on the Paramount Pictures release Case 49 and is currently working on Hannah Montana: The Movie.