One of the best brands of children's clothes on the market is Hanna Andersson clothes; they are available either online or in stores in selected markets. Hanna's can't be beat for quality, comfort and resale value. Hanna's don't fade in the wash and rarely pill or show wash wear even if it gets washed daily for months (personal experience)-- and they don't lose their shape,
Hanna Andersson clothes are sized per European sizes; this actually makes it a lot easier to fit the child, it goes by height- the clothes are generously sized so weight doesn't really factor into it.
One of the most popular lines of clothes is the girls playdresses; these are available in all sizes. The dresses are done in opposites in terms of color-- and either come in stripes or dots. The dress will be in coordinating colors and the leggings will have opposite strips, the socks are the same way. These dresses LAST, wash after wash! And then have an incredible resale value; many times over half of what you paid.
The material for the dresses and leggings is knit, so it's gives and is soft. And since they are sized a bit big, your daughter will be able to wear it for more than one season. My daughter has worn the same play dress size for over a year and still can wear it, it will probably fit through next spring.
One of the downsides to Hanna is the patterns can be a bit busy and the color combinations can be a little strange, but they come in a variety of colors, typically you can find something that is appealling to your or your child.