If you would like to but the complete Flower Girl pattern, you can find it on the Wollyonline website. These clothes are a part of it. Flower Girl is one of the most successful Wollyonline patterns ever.
The free English version can be found here
The free German version can be found here
The free Dutch version can be found here
* Please note that this pattern will fit BABY Born and dolls of the same size but I'm in no way affiliated with any doll manufacturer. I create all Wollyonline patterns at home in my craft room.