It's a Bella.
I know it sounds weird as this is absolutely not looking like one but I know the dancer, saw her even perform in this costume at the restaurant. When you can get a very close look at it, you can see the typical beadwork of Bella on the bra-straps and edges of the bra and skirt, typical Bella bra and a built-in belt that they usually use on costumes like this (I saw some more in that style but they are VERY rare).
Bella sometimes does costumes in (for them) pretty unusal styles when you ask for something like that and this dancer has lots of special-mades Bellas.
Plus she writes the designers of the costumes on her webpage and this is signed as Bella.