Avon Sunvale, previously called Avon Starros, was a human female. She was the daughter of Ghirra Starros, a senator in the Galactic Republic, and a member of the Starros Clan. Sunvale, an aspiring inventor, was born around 244 BBY and lived during the High Republic Era. She was once kidnapped, but her uncles rescued her and killed those who had abducted her. This incident frightened Ghirra, leading her to keep her daughter close until she sent Avon to Port Haileap. After the [Great Hyperspace Disaster](/article/great_hyperspace_disaster], Starros, accompanied by her protocol droid J-6, was overseen by Jedi Knight Vernestra Rwoh on a cruiser headed to the dedication ceremony for the new space station, Starlight Beacon. However, bombs detonated on the cruiser, forcing Starros, J-6, Rwoh, Padawan Imri Cantaros, and Honesty Weft to escape in a shuttle, leaving them stranded on Wevo, a jungle moon nearby. After the Nihil captured her, Avon started to understand that some individuals in the galaxy would exploit her and her research for malevolent purposes, making her hesitant to share her discoveries. Instead, Avon created a series of journals that documented her research on crystal theory. She stored these journals in a data cube, along with a message detailing its intended use, and then secured it within her family's vault. Avon implemented a passcode to safeguard the cube. During the Nihil's destruction of Starlight Beacon, Avon was on the station with Cantaros and J-6. She was presumed to have died, but she actually survived because her mother ensured her escape from the destruction.
At some point, Avon disappeared, and her descendants were unaware of her fate, as it was not recorded in the family archives. Thea Starros discovered Avon's data cube when she was young and unlocked it, gaining access to the secrets Avon had left behind. Later, the Galactic Empire seized the cube. Between 3 ABY and 4 ABY, Thea, along with her daughter Mevera Starros and her nieces Sana Starros and Aryssha, embarked on a mission to retrieve the data cube from the Empire.
Avon Starros made her debut in the junior novel The High Republic: A Test of Courage, penned by Justina Ireland. According to the publisher's summary for A Test of Courage, Avon was eleven years old during the book's events. However, Ireland mentioned in a Comic-Con panel that Avon was twelve. Ireland later clarified that Avon was indeed twelve years old during the events of A Test of Courage.