Although Kerubiel can use her (somewhat weak) shapeshift power to change her body muscle and form, she prefers to work out/fatten out in order to change her shape.
She has a deep disgust with shapeshifting and only uses it when she needs it.

also sketched this to show off her morphology more. she has two sets of pectorals, as the second sustains the tiny arms

her usual proportions are fit/somewhat muscly in order to wear hard armor and guns, also her torso/waist is usually somewhat longer than a human's, but retains human anatomy