I am a swiss citizen, my wife is from India. We would like to invite her mother to stay with us for a longer period of time, i.e. longer than 3 months.
From my understanding this would mean she has to apply for a nationales Visa according to eda homepage:
https://www.eda.admin.ch/countries/india/de/home/visa/einreise-ch.html
She does not intend to come here for studies or marriage, which would leave Familiennachzug, usw. (what other reasons are meant here?)
For a country outside europe, Familiennachzug only refers to spouse and kids younger than 18 years according to these sources:
https://www.ch.ch/de/familie-und-partnerschaft/familiennachzug/
https://migration.lu.ch/-/media/Migration/Dokumente/Einreise_Aufenthalt/FamiliennachzugdurchPersonenmitNLBewilligungnichtEU.pdf?la=de-CH
Is there another way to let her stay here for more than 3 months before going back home?