Tiffany begins her witching career at nine, upon being scouted out by the "witch finder" Miss Tick, after things from Fairyland begin making an entrance. 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. For this she earns the respect of Granny Weatherwax, a significant achievement in itself. Although Tiffany is too young at the time to be an official witch, Granny gives her an imaginary invisible hat to boost her confidence. Such is the power of belief on the Disc that this hat keeps off the rain.

As a witch, Tiffany possesses First Sight, the ability to see 'what is really there' (as opposed to second sight, which shows people what they think ought to be there). She also possesses Second Thoughts, which are defined as 'the thoughts you think about the way you think'. Whilst other witches are said to have this trait as well, Tiffany also recognizes some of her thoughts as Third Thoughts (the thoughts you think about the way you think about the way you think), and Fourth Thoughts (the thoughts you think about the way you think about the way you think about the way you think). All these thoughts sometimes cause Tiffany to walk into door frames.