"A Trekkie's Tale" is a very short story about Lieutenant Mary Sue, who upstages the entire crew of the USS Enterprise and then dies tragically. The Mary Sue in the story is a parody Sue rather than a straight version, and is responsible for nearly single-handedly raising awareness of the Sue problem in fanfiction. Before Lieutenant Mary Sue, some authors protested against unrealistically beautiful, skilled, characters who twisted the plot out of shape; but the phenomenon was not well known (except to the Flowers). The creation of Lieutenant Mary Sue coincides with the Star Trek fanfic explosion, an event much like the later, larger Lord of the Rings, Harry Potter, and Twilight fanfic explosions in that it swamped the PPC with badfic; but thanks to the popularization of the Mary Sue concept, the PPC was able to recruit more World One natives than it ordinarily would have, and keep up (to some extent) with the sheer volume of badfic.
The PPC has not yet encountered her; she may be in hiding, or the records of such a meeting may simply be unavailable. Given "A Trekkie's Tale" is considered goodfic, encounters with her are unlikely.