Daria Morgendorffer
D. Morgendorffer was a “known associate” of Jenny Everywhere in at least one incarnation, along with J. Lane, according to a wanted poster jointly put up for Jenny by a number of organisations who wished to bring her in for questioning. (PROSE: Wanted for Questioning)
Behind the scenes
A character originally introduced in the adult animated TV series Beavis & Butt-Head before getting her own spin-off, Daria, Daria Morgendorffer was depicted in her two series of origins as an intelligent, practical, and intensely cynical teenage girl, looking on with deadpan sarcasm at the antics of more eccentric members of each show's cast.
Although their connection is not highlighted, J. Lane on the poster is presumably Jane Lane, Daria's inseparable high school friend. When and how they met Jenny Everwhere we can for now only speculate, but notably, there is precedent for Daria and Jane running into dimensional travelers. Although its canonicity is disputed by fans, the episode Depth Takes a Holiday showed them meeting anthropomorphic holidays and traveling briefly to another dimension.