Learning German in Germany

I agree that being in a country where they speak the language gives a lot of opportunity to learn it better. One is emerged in it and can experience it in action rather than just theoretically out of text books.

It is correct that one cannot work on a language school visa. One can work part-time on a study visa for university. University is for upper levels of study and learning a language from the beginning is not seen this way unless it is a foreign (other than German) language. One can learn Germanistic, which is the equivalence of learning English in an American University – it will assume one knows the basics and be focused on the complexities. One also doesn’t major in mathematics in University if they haven’t learned simple arithmetic. So to learn German one needs to go to a language school or get a private tutor.

To study at University in a German taught program (most of them) will usually require a C1 level. To learn German parallel while doing an English taught program is theoretically possible but takes a lot of discipline and would not leave time to work. And one should know work on a study visa is strictly limited to part time, details of which are covered in multiple other threads on this site. But the only jobs a student is likely to get are low paying ones like working in food service, not likely enough to live from. And even if one works, they still need to have the required amount (currently a bit over 10,200 Euros) needed annually in a blocked bank account to get the study visa if needed (any non-EU person).

And while most but not all Universities in Germany have some student housing, it is usually very limited. The vast majority of students find their own accommodation; usually in shared apartments (known as WGs) with other students or young people. Lots of long threads about this subject on this site as well.

How old is she and where is she in her education?

Has she finished high school?

A Bachelor's degree?

Master's?