In the pre-new 52 continuity, June always exhibited a passion for science. At a young age, she attended the Future Young Inventors exhibition in Las Vegas, Nevada where she met other intellectuals. She became an honorary member of the Challengers of the Unknown. Since the new 52 she is the de facto leader of the team, a group that is based around a reality television show.
June's first appearance was in Showcase #7 in 1957, reprinted later in Challengers of the Unknown #75 - Ultivac is Loose! In this story, she advocates for herself as a replacement for Rocky Davis, who had moments earlier apparently died in defense of Ultivac against its jealous co-creator, the Nazi war criminal Felix Hesse. However, Davis survives and she is relegated to a support role for the male Challengers for many years.
In her earliest appearances she served as a female sidekick to the otherwise all male Challengers. Since the new 52 reboot of the team she now appears as its leader. She has also been recently established as the aunt of Jody Robbins.
Major Story Arcs
As a creation of the silver age of comics, the majority of the Challengers stories fit the format of the time, namely that each story was told in a single issue with very little overlap between issues. Furthermore many of the teams stories were more in line with adventure-comic style storylines which did not carry over well between issues. As the team developed they struggled to maintain a strong popularity, and thus many of their story arcs were not noteworthy as they did not progress substantially. Since the new 52 reboot the character has been used as the leader of the new Challenger as they are comprised of a reality television roster and discover a greater path after a plane crash in the Himalayas.
Powers and Abilities
June is a regular human being with no known super powers. She is of a high intelligence. Although she is not in exceptionally great physical form (at least compared to many other non-superpowered characters) she nonetheless has a knack for surviving dangerous situations and performing acts requiring some athletic ability.