It is actually bresiliennes because ‘les filles’ is feminine (une fille). When there is an adjective that has an -ien ending, -ien is for masculin and -ienne is for feminine.
Is there a story attached to this? They could be from anywhere depending on what passage or story you read. But I would go for “Columbiens” based on the knowledge I have right now! If the girls are also Canadian as well I would choose that answer. Hmm...maybe this will be more use to you then that answer...
Columbiens- Canadians
americain- American
bresiliennes- Brazilian
vietnamien- Vietnamese
These are translating the French to English for you. I hope this helps!~ Your lovely strict boi, Mr.Han
