I think the accessories and shoes push it into semi-formal status. It's hard to really comment on the dress b/c I don't know what kind of material it is. I think it will look really good once it's all put together.
I love everything. Your daughter has great taste. While the flats are really pretty I think a shoe with a little bit of a heel would be a little dressier. A kitten heel would be perfect. I hope she has a wonderful time!