Yes and no; the main difference between Juniors and Womens (or Missy, or Contemporary) sizing is that Juniors is build for a “straighter” body type — it is meant for younger girls who have not yet put on their “womanly” curves. So, if your waist and hips are pretty close in measurement and your backside is not especially curvy, your Junior size for 16 will be 17. If you have broader hips and a smaller waist, or a very curvy backside, you will probably look better and be more comfortable in size 19.

If you’re ordering from a catalogue, I very much suggest getting both sizes and sending back whichever one does not work as well. If you can only get one, then get the 19. Most people look better in something a little too big than in something a little too small.