Year Title Role Notes 1992, 1995 Roseanne Young Jackie 2 episodes 2006 Law & Order: Criminal Intent Wendy Episode: "Vacancy" 2006 Conviction Audrey Knowles 2 episodes 2006, 2008, 2010 My Boys Waitress 4 episodes 2007 Cold Case[1] Melinda Levy '82 Episode: "Justice" 2008 Private Practice[7] Lisa Episode: "Equal & Opposite" 2009 Ave 43 Janet 2 episodes 2012 Grey's Anatomy Katy Noonan Episode: "Beautiful Doom" 2013 Second Shot Krystal Munson Episode: "If It Ain't Fix, Don't Break It" 2016 The Family Jane 9 episodes 2016 NCIS[7] Harpers Ferry Police Officer Kristen Fields 2 episodes 2017 Liv and Maddie Marlow Episode: "Tiny House-A-Rooney" 2017 Scandal Samantha Ruland 9 episodes 2017–present Young Sheldon Mary Cooper Main cast