Joanna is a recurring character, who first appears in "Petergeist" and then later on in "Movin' Out (Brian's Song)". She works in a library and is invited to a surprise party Stewie organized for Brian. She is known to have a very annoying way of laughing and usually laughs at her own jokes. However, she is gets along well with Stewie, who took an instant liking to her upon their first encounter.
Joanna is voiced by Alex Borstein.