She also appeared in two spin-offs: the one-off special K9 and Company: "A Girl's Best Friend", and The Sarah Jane Adventures. The former lasted only one pilot episode, while the latter lasted 53 regular episodes for 27 stories, plus 1 mini-episode. (The number on SJA comes out odd because while all stories were formatted as two-parters, the initial story aired as a one-hour special.)
Sarah Jane also appeared in various spin-offs, these include the LP "The Pescatons" (audio story), "Exploration Earth" (audio story), an audio series for Big Finish Productions that lasted several "seasons", and the direct-to-video release "Downtime" (Reeltime Pictures video).
Sarah Jane Smith has also appeared in multiple novels, short stories and comics for TV Comic, World Distributors Annuals, Doctor Who Magazine, IDW, the official Sarah Jane Adventures website, Virgin Books and BBC Books.
For a list of stories, see Sarah Jane Smith - list of appearances. (No total is given & the novelisations are listed separately from the original TV stories.)