The second season She-Ra episode "Bow's Magical Gift" has the rather forced and rather blatant appearance of the Star Sisters. Bow demonstrates his newfound magical weapon while Tallstar, Jewelstar, and Starla watch. For those that do not know, the Star Sisters were one of the last line of toys to be released by Mattel for the She-Ra series, but even though prototype figures were made and advertised, the figures sadly never made it to toy shelves. Thus the Star Sisters, who could have gone onto bigger and better things had the toys and the series continued, remain a very small part of She-Ra's history.
(click on the images to see them at full-size)