A sister to the human male Jon Wittick was a female individual living in the era of the High Republic Era. By the time 231 BBY arrived, she had at least two children, one of whom was a son. In that year, Wittick intended to meet his sister and her children at the Republic Fair, located on the planet Valo in the Outer Rim; the son was particularly excited to view the Innovator, a research vessel of the Elite-class. However, during the attack on the Republic Fair by the Nihil pirates, the Innovator was sunk into Lake Lonisa. Later in that same year, Wittick, who was working as a counselor on the Republic prison ship called Restitution, spoke to Sal Krost, one of the ship's prisoners. Unbeknownst to Wittick, Krost was actually Lourna Dee, the Tempest Runner of the Nihil, who had masterminded the Nihil's attack on Valo, and he revealed his plans to meet his sister at the Republic Fair.
The High Republic: Tempest Runner, an audio drama from 2021 penned by Cavan Scott and released as part of Phase I of Star Wars: The High Republic, mentioned Jon Wittick's sister.