Courtney Healy Henggeler, born on December 11, 1978, is an American actress who is best known for her character Amanda LaRusso on the Netflix comedy-drama show Cobra Kai. Her most well-known role is her character Missy Cooper, Sheldon Cooper's twin sister on The Big Bang Theory. Early life and education Henggeler was born in Phillipsburg, New Jersey. She was raised in Pennsylvania's Poconos which is where she resided until she reached the age of fourteen. Then she relocated to Seaford, New York, located on the South Shore Long Island. She completed her studies at Seaford High School in 1997. She was enrolled at SUNY Fredonia, but she was unable to finish her studies. A few years later she relocated to Los Angeles, where her first acting classes were taught. Patti her childhood friend who helped her audition for the production at her high school, Carousel.