Update: Added Pony version trained on Pony Realism.

Actress Clemence Poesy in her role as Fleu Delacour. Trained on 41 images from Harry Potter and the Goblet of Fire, Harry Potter and the Deathly Hallows Part 1, and related promotional material.

You can prompt for her Beauxbaton uniform with the tag "beauxbatons uniform", however it really only works well for medium shots and portraits. I think you'd need a lora specifically for the Beauxbaton uniform to really do it justice. You can also prompt for her outfit from the 3rd task in Goblet of Fire with "athletic uniform".