Plaza graduated from Ursuline Academy in 2002 and New York University's Tisch School Of The Arts four years later, though she suffered a stroke in 2004. She was left temporarily paralysed with expressive aphasia, meaning she could not speak for a short time, though she has made a full recovery and suffers no lasting effects of the incident. It took place during a comedy improv class, with her classmates thinking she was acting. She said: "My two friends that were with me at the room at the time thought I was doing a bit with them. And they kept saying 'stop it,' like they thought I was joking or something."