Conversation so far:
How was Lisa Simpson developed?
Matt Groening, in the lobby of producer James L. Brooks's office, hurriedly sketched his version of a dysfunctional family and Lisa Simpson was named after Groening's younger sister.
What is Lisa Simpson's IQ?
Lisa Simpson is said to have an IQ of 159.

Question: Who is Lisa?
Self-contained rewrite: Who is Lisa Simpson?