She was known for her unusually scientific methods of testing and recording results, mainly in the fields of pharmacology and the uses of herbs. The cottage in Mad Stoat had a vast library for the region, as many as twelve books. This sort of literacy was rare in Lancre, and greatly mistrusted by Granny Weatherwax (a witch of few words, and fewer written down). Goodie may have inspired the term research witch. She was the mentor of the young Magrat Garlick, later Queen of Lancre.
Goodie Whemper died somewhat prematurely, for a witch, as the result of another experiment to determine if her broom could remain airborne if you pulled out the bristles one by one whilst in flight. According to the raven she had trained to act as the in-flight black box recorder the answer was 'no'. Magrat, and later Agnes Nitt, succeeded her in the cottage.
One of Goodie's research triumphs was discovering the ideal apple and just the right size of paring knife to be used in the classic spell to discover who you will marry, ie the one where you peel an apple in one long unbroken strip, throw the peel backwards over your right shoulder with the left hand, and then look to assess whose initials it spells. Unless a Golden Billet is peeled with a two inch paring knife no wider than half an inch, the loved one's name will invariably be SCSSSC.