<Tr> <Th> Occupation </Th> <Td> Actress </Td> </Tr> <Tr> <Th> Years active </Th> <Td> 1997--present </Td> </Tr> <P> Margo Cathleen Harshman (born March 4, 1986) is an American actress known for her role as Tawny Dean on the Disney Channel series Even Stevens . She is also known for her role on The Big Bang Theory as Sheldon Cooper's assistant, Alex Jensen, and as Delilah McGee, Timothy McGee's paraplegic wife on NCIS . </P> <P> Margo Harshman was born in San Diego, California . She has two older sisters, one older brother and one younger brother . Harshman lived in La Costa, San Diego County, California and attended school there until she was 12, after which she moved to Orange County, California . There she finished the rest of her education, first at Hewes Middle School and then at Foothill High School . Harshman now lives in Los Angeles . </P>

Who plays alex in the big bang theory