Tiffani Amber Thiessen (born January 23, 1974) is an American actress. Her roles as Kelly Kapowski on NBC's Saved by the Bell (1989–1993) and its spin-off media, and as Valerie Malone on Fox's Beverly Hills, 90210 (1994–98) established her as a teen idol of the 1990s. As an adult, she has played Wilhemina 'Billie' Chambers in Fox's Fastlane (2002–2003), Natasha Drew in ABC's What About Brian (2007), Elizabeth Burke in USA Network's White Collar (2009–2014), and Lori Mendoza in Netflix's Alexa &