Meninas is a Quincy and a member of the Wandenreich's Stern Ritter with the designation "P".

Meninas is a tall, well-endowed girl with long hair. Her attire is a variation of the Stern Ritter's typical white uniform, consisting of a frilled skirt, frilled gloves, frilled boots, leggings, a belt with a heart-shaped buckle, a large bow around her neck, and a white cap, which features a black peak and the Wandenreich insignia emblazoned on its front, turned sideways.

(Source: Bleach Wikia)