A jumper is a great dress choice for a girl (of any age really). Whether you dress them up with a frilly blouse, or dress them down with a t-shirt, the end result is the same ... cute and comfortable.
McCalls M4573- This cute jumper is knee length and has a scoop neckline and back zipper, along with several variations. Add in pockets, trim appliques to meet the personality of your girl.
See & Sew (By Butterick) 5138 - This charmer has a V-Neckline with fitting bodice darts with front button closure. Wear it as a jumper on cooler days, and forfeit the top and let it be a sleeveless dress on those warmer days. This one is perfectly simple.
Simplicity 5131 - This is a vintage dress from the 1950s. This jumper has a bit of the unusual, it not only has an adorable flared skirt, but it is a wrap around with a high round neckline in the front and a Deep V in the back.
McCalls 6194- This one is the little older girl, adding in stylish flair of a deep scoop or V neckline, front buttoned and a dropped waist. And, if that isn't enough - Pleats !
These patterns are available in my shop (at least as of this writing). Just click on the link should you be interested. At any given time, I'm sure there are more girls jumpers as well.