Ernest Balliol and his daughter, Isolde Balliol, are played by real-life father and daughter Ronald Pickup and Rachel Pickup.
Since the actors playing Ernest and Isolde Balliol are actually father and daughter, genuine family photos were used to create the collages in Isolde's room.
The "Jefferson Airplane - Grateful Dead" poster in Isolde's room is from the series of concerts (eight in all) that the two bands performed in the O'Keefe Centre (now known as Meridian Hall) in Toronto, Ontario, during the period 31 July to 5 August 1967. One online seller describes it as "among the rarest of posters" and states that there are unconfirmed rumours that the original lot of posters were confiscated by Border Patrol.
The episode name, "The Magician's Nephew", is probably a reference to the famous children's book of the same name in the Narnia series by C.S. Lewis.
Characters Isolde Balliol and Tristan Balliol are named after the characters Tristan and Isolde from a tale made popular in the 12th century about an adulterous love between the Cornish knight Tristan and the Irish princess Isolde. In the story, Tristan and Isolde are lovers, whereas Isolde and Tristan Balliol are brother and sister.