Winna Di Yuni was a female Jedi Knight during the time of the Old Republic around the time of the Battle of Naboo. Winna was one of the best Jedi Healers of her generation. Serving the Jedi Order in the Jedi Temple on Coruscant, Winna studied there and was available to help with any number of problems that might arise.

During one such situation, Winna was asked to investigate the poisoning of the man Didi Oddo. During her investigation, Winna was able to determine that Oddo had been poisoned by a chemical originating from Arbor Industries. This information proved to be crucial to Jedi Knight Obi-Wan Kenobi in dealing with the mad scientist Doctor Jenna Zan Arbor, who had kidnapped his Master, Jedi Master Qui-Gon Jinn.