After the Ghost crew hears Senator Gall Trayvis's broadcast claiming that "one of the Republic's greatest peacekeepers, Jedi Master Luminara Unduli, is alive," Kanan says that "she was a great Jedi master, brave, compassionate, disciplined" and tells Ezra that "she'd made an excellent teacher for you." From the moment she's introduced, Luminara is presented almost as the epitome of the Republic-era Jedi, but in this time period (the "dark times" of the Empire, as Obi-Wan describes it in A New Hope), she's more suited for this idealization than some other Jedi. Luminara's name is related to lumen (gen. luminis), the Latin word for light, so in a way, she's the embodiment of the light side of the Force and acts as a symbol of the old Jedi order.
[EDIT: According to the Star Wars website, each part of "Spark of Rebellion" is its own episode (S1E1 and S1E2), but I thought the two parts constituted just one episode (this is how it's listed on IMDb), so my numbering for the first season is off.]