Based in the Netherlands, Oilily is known for their vibrant colors and designs. They carry clothes for boys and girls as well as women and also have a limited home line of bags and perfume and linens. 
https://www.oilily.com
Their products are very expensive, but you can often find them on ebay as well.
Designed for girls ages 7 and older, Hayden Girls is a boho clothing company located in California.
https://www.haydengirls.com
An East Coast clothing store for girls catering to unique multicolored, layered looks. They have the most awesome headbands.
http://mustardpieclothing.com
The headbands themselves run about $15. Check ebay for less expensive options.
A more sophisticated kids clothing line from Europe featuring highly tailored clothes. They offer clothes for boys, girls and women.
Another clothing company for girls from the Netherlands. They describe their clothes as magical, sweet and renewing.
https://mim-pi.com/
Their slogan is Where Everyday is a Celebration, describing their clothing as romantic and magical.
https://www.jottum.com
