My daughter is leaving in 3 weeks to study abroad in Paris. Her passport is with the French Embassy being processed for a student visa. That visa requires her to leave Schengen countries within 14 days after her classes end on May 31 (if we understand correctly). She was just offered a summer internship with a division of the U.S. government in Geneva to start in June, for 10 weeks. They state that she requires a visa, but does not explain how to obtain it.

What sort of visa must she get for her unpaid internship in Geneva?
Can she get the visa while she is studying in Paris?
Will she be required to return to the U.S. before going to Geneva?

There is a place called the Swiss Embassy they should have an office in your country and they should also be able to answer all your questions

In theory, the "division of the US government in Geneva" should obtain all necessary documents from your daughter and manage the application process themselves. In theory, your daughter should apply/obtain the work permit from her home country. In theory, this takes around three months.

There are exceptions, of course. In my efforts to obtain a work permit for an unpaid internship, for example, I did most of the application process by myself, I applied from within Switzerland and I waited almost six months. In the end, it was rejected for no clear reason (still waiting on a letter).

Best get started right away and start asking questions to the employer, voicing your concerns.