My hips are very narrow and i don't have much of a waistline. in a-line skirts and anything that sits below the waist, i wear a size 6. skirts like this with a defined waist almost never work for me because of the waistline. if this is typically your style of skirt, i think it will run large because the waistline is more generous than usual. 

 i tried it on in the store today and bought it in a size 8. it's very comfortable and cute and will be easy to pair with different things.