I'm not exactlly slim (5'3" and I wear a large) but this is a great looking skirt the shirring on the hips makes ones hips look smaller while taking attention away from ones stomach. I got this skirt in all the colors! If you're around 150 Lbs the large should fit, me I go UP and down in weight.  I want to be cautious as everytbody's body type is different, some of us have a stomach ,some carry their weight in the "butt". I've seen women with flat 'butts" but wide hips. Some women wear their skirts so tight I wonder how they can walk. But again I think if you are 150 lbs. with standard measurements the Large should do nicely , remember it is a pencil skirt and therefore tight. The point is, we are all beautiful, right girls?