born in highland park, illinois and studied san francisco state university. borstein was trained in comedy at the acme comedy theatre, near hollywood, california, and was selected to join madtv after being searched by talent agents who noticed her comedy work at the theatre. borstein was a writer and voice actress for several shows like; "casper, pinky and the brain" and "power rangers: zeo", "powerpuff girls", before joining the cast of "madtv" as a featured player, and as a theatre player in 1997.