I really love this Hanna dress and always try to grab it when it's on sale:
https://www.hannaandersson.com/girls-clothing-dresses/68125-036.html
They do short sleeve and sleeveless versions in the spring and summer as well, plus right now they have some velour versions. It has great stretch so my DD can wear these for like three years, with the third year it being more of a tunic length and worn with leggings or shorts. The quality is really good and the patterns don't fade as fast as other brands (ahem, Tea).
Also, if you have a dress-loving girl, I recommend checking out H&M's organic cotton. We'll stock up with a set like this most years and it's a cost-effective way to stock up:
https://www2.hm.com/en_us/productpage.1034536002.html
I've also found really cute cotton dresses at Target (the Cat & Jack line), but have found that their stuff for girls is not as cute as the stuff for toddlers. Or at least that's been my experience the last couple years, since DD aged out of toddler clothes.