Theresa Mulligan Rosenthal is a TV writer and producer, working on such shows as "Lady Dynamite," "How I Met Your Mother" and "Whitney." She started out improvising in the '90s in Chicago and was a member of Second City Touring Company, Second City Northwest and Jazz Freddy. We talked to her about taking improv classes with her mom, how she went from being an improviser to writing for TV, and how she has overcome her insecurities.