The earliest scripts for the series had a completely different origin for the character of Susan, that of an alien princess named Suzanne – saved by the First Doctor from a world different from his own.

[2] Carole Ann Ford recalled that she was told her character would be "an Avengers-type girl – with all the kapow of that – plus she would have telepathic powers.

[4] While the original outline for the series did not intend the pair to be related, writer Anthony Coburn created the family tie that Susan was the Doctor's granddaughter.

According to founding producer Verity Lambert, "Coburn felt there was something not quite proper about an old man travelling around the galaxy with a young girl for a companion.

[6] Susan is introduced in the first Doctor Who story, An Unearthly Child (1963), with the first episode focusing on her as an unusual teenager with an advanced knowledge of history and science.

During the events of that story, Susan falls in love with David Campbell (Peter Fraser), a young freedom fighter in the 22nd century.

The Doctor, realising that Susan is now a grown woman and deserves a future away from him, locks her out of the TARDIS and leaves after a tearful farewell.

[12] Ford reprised the role of Susan on television in the 20th anniversary special "The Five Doctors" (1983), but no mention of David, or what became of him, was made on screen.

"[28] In the Class episode "For Tonight We Might Die", Susan's name is displayed on the roll of honour at Coal Hill Academy, along with Clara Oswald and Danny Pink.

This is dismissed after the villain of the finale, Sutekh, reveals that upon looking inside the TARDIS, he saw "(Susan's) name", and decided to use her as a trap to lure in The Doctor.

He reveals that the recurring Susan Triad character, is in fact an apparition of his own design, and he has been planting them everywhere the TARDIS has landed since the TV story "Pyramids of Mars."

This story, "Birth of a Renegade", depicts Susan as a descendant of Time Lord founder Rassilon and the last surviving member of Gallifrey's royal family, unrelated to the Doctor.

This account, part of the "Cartmel Masterplan", was not used in the programme, but was used as background for several of the Virgin New Adventures novels, most notably Lungbarrow by Marc Platt.

[35] The 2001 Telos novella Time and Relative takes place just prior to An Unearthly Child and involves Susan and several of her classmates from Coal Hill School trying to survive an alien invasion of Earth by a race of ice beings called the Cold and at the same time convince the Doctor to stop the attack.

In the 2017 novel A Brief History of Time Lords, an image of Susan is shown as one of the things that the Doctor took with him when leaving Gallifrey, although she is listed as the President's daughter.

She helps the Time Lords form an alliance with the Sensorites to gain the aid of their telepathic circuits- also recruiting Ian to act as a diplomat in the process- ("Sphere of Influence") and later missions including capturing a Dalek agent on Florana ("The Uncertain Shore") and preventing a plan to configure the vortex-dwelling Orovix as a weapon against the Daleks as Susan recognised that they were too dangerous ("Assets of War").

In the 2013 BBC drama An Adventure in Space and Time, which told the story of the first three years of the show, Claudia Grant played Carole Ann Ford.

In the Dalek-infested London of the 22nd century, the Black and Red Dalek and two Robomen walk past a sign reading: ″IT IS FORBIDDEN TO DUMP BODIES IN THE RIVER″, as well as an inconspicuous police box, not recognising it as Tardis.

In an interview following the skit, Tovey harboured hopes of a follow-up to the two Cushing films centering on an adult version of her Susan, having taken on her grandfather's mantle as an adventurer in time and space, these plans never materialised.