A Lookback Of Every Characters In The Big Bang Theory. Who Is Your Favorite?

Yeardley Smith as Sandy

In 2010 in the episode “The Einstein Approximation”, Yeardley Smith appeared on The Big Bang Theory. It’s also the same episode where Sheldon works at the Cheesecake Factory alongside Penny. Fifty-three-year-old Smith is well known as the long-running character Lisa Simpson from The Simpsons. Aside from acting, she’s also a comedian and a writer.

Yeardley Smith As Sandy