Thank you guys very much,
And yes, I just want her to get a Shengen visa only, but as it's almost impossible to have it from Vietnam without an invitation letter (they took me 8 months to have a visa, even my company base in Geneva and supplied all the required documents), and the posts I found about invite people to Switzerland only talk about permit B or C, then I confused if permit L, as I had, can invite people or not?
Now I need to go fast with all the paper

Thank you very much!