Kristin Wells first appeared in Elliot S! Maggin's novel Superman: Miracle Monday as the secret identity of Superwoman. She was later introduced into comics continuity as Superwoman. The name has recently been used as a pseudonym for Karsta Wor-Ul.
Wells is a descendant of Jimmy Olsen who lives in the 29th century (like Jimmy, Wells is a freckled redhead). She is a journalism student whose graduate thesis was the successful investigation of the origins of the holiday known as Miracle Monday, using a form of time travel technology that had just began to be used by the public in her era. She then became a teacher, but became interested in finding out the identity of Superwoman, the last superhero from the 20th century whose secret identity had never been discovered. She managed to convince the authorities of her time to send her again to the present, at the moment when Superwoman was supposed to debut, helping Superman fight a villain called King Kosmos. Wells soon deduced that she herself was supposed to become Superwoman, and, using some of the technology she had brought from the future which (conveniently enough) allowed her to have superpowers (including flight, teleportation, empathy, precognition, and telekinesis), she disguised herself and helped Superman defeat Kosmos. She revealed the truth to Superman, then returned to the future to make the information public. Wells realized she would have to periodically return to the 20th century to ensure that all the historical events Superwoman was part of were fulfilled.
However, during one of those trips, a malfunction of the time travel process---which was still imperfect---left Wells trapped in the past, suffering amnesia. This caused her boyfriend to lead a movement against time travel that eventually resulted in it being banned. Years later, Wells returned home, apparently having recovered her memories, and was reunited with him. The details of her later activities in the present (and of her return to the future) remained unrevealed. The 29th-century Kristin's last appearances to date are in the non-canonical story Superman: Whatever Happened to the Man of Tomorrow? in 1986, and a brief cameo as a one panel ghost in The Kingdom: Planet Krypton in 1999.