Short answers, pulled from the story.
April O'Neil first appeared on the 14th of November 1984 in the original Mirage Comics by Kevin Eastman and Peter Laird. She was introduced as a red-haired computer programmer working for Baxter Stockman before fleeing to the sewers of New York City.
Judith Hoag played April O'Neil in the 1990 live-action film produced for a wider audience. She portrayed a television reporter working for Channel 3 news under Charles Chuck Pennington who became friends with the Turtles and Splinter.
April O'Neil was mutated into a turtle in the 1994 Teenage Mutant Ninja Turtles Adventures series produced by Archie Comics. This transformation made her the first official female turtle introduced to the series three years before Venus de Milo's debut.
April O'Neil was reimagined as a plus-sized teenage black girl who wore glasses and was the love interest to Leonardo in the 2023 film Mutant Mayhem. Voiced by Ayo Edebiri, she was depicted as a camera-shy aspiring journalist who became a confident ally to the Turtles.
April O'Neil possessed exceptionally strong psychic powers in the 2012 animated series as a half human half Kraang-mutant. Her abilities allowed her to hear far-off sounds that Splinter could not detect and she eventually learned to develop these powers drastically throughout the fourth season.
April O'Neil served as a faithful friend and ally to the Turtles in the 2003 cartoon series while developing a closer relationship to Donatello. She utilized her scientific expertise to aid the Turtles and eventually became a formidable warrior by wielding a katana in the special episode Turtles Forever.