The Voeburtite/Heirloom tunics of casting and healing come to mind when I think of feminine Disciple of Magic gear. It's practically a mini dress design-wise, and while some people might like that (myself included), I can imagine most dudes would glam that off in a heartbeat.

What casters and healers need are more outfits like Exdeath's and Golbez's heavy armor, or Seymour's robes with the open chest and tattoos.