Anonymous wrote:Nordstrom kids' department goes up to size 12-14, I think, depending on what style you are looking for.
OP, I think the reason you aren't getting many answers is because it's actually hard to find brick and mortar stores that carry nice merchandise.
When my daughter was that age, I found dresses at Nordstrom or online but they weren't necessarily good quality ones online. Also, try Bloomingdales.
I also think (if you were willing) you could make an appointment at Lilac Girl in Bethesda. They carry this brand which is hard to find in stores but please check out their website and consider ordering from here:
https://katiejnyc.com/collections/tween-day-dresses