The Pettibone family moves to Avonlea in the winter of 1907. Isolde ("Izzy"), Morgan and Arthur are the daughter and sons of Clive and Jessica Pettibone.

Clive was part of the British army and served overseas. After moving to Avonlea, Clive becomes a schoolteacher.

Jessica passed away before the family moved to Avonlea.

Izzy is considered to be a tomboy and later gets romantically involved with Felix King.

Morgan is the middle brother. He was expelled from the military acadamy.

Arthur, a tempered young man, decided to be a veterinarian and studied the practice in Toronto. He later returns to Avonlea and wants to become romantically involved with Felicity but her heart belongs to Gus.

Clive Pettibone later marries Muriel Stacy.