The thing most notice first about Bastila is that she appears to be somewhat translucent, light passes through her and her shadow looks more like that of a stained glass window than the usual blurry darkness.  Only shortly their after do any number of other unusual traits become apparent.  Large feathered wings, a soft coating of short fur, and big ears atop her head each more like that of an animal than a human.  But in every other way she seems to be a slim, short, young woman no more than five feet tall and well under a hundred pounds if she follows the typical hollow boned state of other winged creatures.  Even among other adventures she tends to stand out a little bit more in that she carries no obvious weapons other than a dagger that looks more like a tool, and wears no armor.  If this wasn't an obvious enough clue that she wields at least some sort of magic the half dozen bright and shiny stones orbiting her head just outside her field of view would give that impression to most.