Steffany is a girl at Ranting Lane who The Three Musketeers encounter during The Snottle, who possessed a snottle egg which she wore around her neck, thinking it was a lucky charm of some sort. The egg made the nose of whoever came into close contact with it run, and eventually they would sneeze loudly, letting off lots of snot in which a picture of the close future would appear. This egg came from her grandmother, who used it to make a profit by predicting the future, using the nickname "Nostrilamus" (a play on the famous astrologist Nostradamus). Through the help of Jiggy, Angie, and an assistant at a garden centre who had past experience with it, she discovered the true nature of the snottle egg, and eventually watched it hatch into a Snottle.

Steff is an environmentalist, as is her mother, who campaigns to stop trees from being destroyed needlessly.

Her only main feature is in The Snottle, she is not mentioned again until Rudie Dudie, where she is briefly mentioned as having pulled open the curtains for a school performance.