Good News Everyone!
series has but a few spinoffs: a series on science, and a smattering of young adult novels set in the same universe. Of the latter, only one character has inspired Pratchett to write more than a single book about their adventures, and that's Tiffany Aching, junior witch, dairy maid, and friend of the Nac Mac Feegle, a tribe of "pictsies" best described as that really weird dream you had after falling asleep facing a Braveheart
poster at the end of an evening of bawdy drinking and a Smurfs
It's my duty to inform you that Ms. Aching may be coming to a theater near you.