She is the main character in The Wee Free Men, A Hat Full of Sky, Wintersmith, I Shall Wear Midnight and The Shepherd's Crown.

[4] A young witch (9 during The Wee Free Men,[5] 11 in A Hat Full of Sky,[6] 12 and 13 in Wintersmith,[7] almost 16 in I Shall Wear Midnight,[8] and in her late teens in The Shepherd's Crown),[9] Tiffany hails from the Chalk, a Barony and a region of Downland Rimward of the Ramtops.

Her late grandmother, Sarah 'Granny' Aching (who died 2 years prior to the events in The Wee Free Men), was a shepherdess, and by Ramtop standards she was also a witch, although witchcraft was frowned upon on the Chalk until Tiffany openly practised it.

Granny Aching was a friend of the Chalk's Clan of Nac Mac Feegles (an army of tiny, tattoed in blue colour, rowdy, drunken and vaguely Scottish 'pictsies'), and they have befriended Tiffany as the new "hag o' the hills".

She later leads the Feegles on a journey into Fairyland to rescue Wentworth, her toddler-age brother, as well as Roland, the young son of the local Baron, from the Queen of the Elves.

[10] Her body becomes vulnerable to infestation by a "hiver," (a gestalt entity of minds from the dawn of time) which uses her power to harm and cause chaos, using Tiffany's suppressed thoughts and desires as a basis.

The Wintersmith continues its advances, even attempting to create a human body out of snow and miscellaneous elements using a recipe from a children's song.

Like her grandmother, she appears to have a symbiotic, spiritual link with the hill lands on which she lives, and as such has shown herself to be strongly protective of the region and all its inhabitants.

On several occasions, Tiffany has induced in herself a state of total mental clarity, becoming completely aware of every sensation, life-form and object around her, including the land itself.

In Wintersmith she demonstrates a high level of skill in the art of magical self-concealment, and also learns how to absorb heat from any available source (including the sun) and channel it out into the world, without being touched by it herself.

She generally precedes the use of the latter art with a sort of mantra, in which she states that she willingly chooses to undertake the dangerous action, and is prepared to accept full responsibility for all its consequences.

In I Shall Wear Midnight it is revealed that in the future, Tiffany is able to exert a limited amount of influence over events throughout the timeline with the help of Eskarina Smith, the main character of Equal Rites.

At the climax of events in I Shall Wear Midnight, it is revealed that Tiffany, as the Witch of the Chalk, also has powers and authority not unlike a Justice of the peace; she is able to perform binding marriage ceremonies, and judge and deal out punishment onto the deserving.

She is friends with several of the Nac Mac Feegle, including Rob Anybody (originally, but accidentally, her betrothed), Daft Wullie (somewhat clueless), William the Gonnagle, Hamish, and Not-as-big-as-Medium-sized-Jock-but-bigger-than-Wee-Jock Jock.

Roland comes to have great affection for Tiffany and takes the role of the mythic hero, attempting to rescue her from the Underworld[10] and from the romantic attentions of the Wintersmith.

During the fourth book, I Shall Wear Midnight, it is revealed near the end that she has entered into a romantic relationship with an intelligent young guard, named Preston, who aspires to study medicine at the Lady Sybil Free Hospital down in the city of Ankh-Morpork, under Dr John Lawn, and further wishes to start a medical practice of his own up in the Chalk.