We are preparing a manuscript to be submitted to a peer-reviewed international journal. We have an author that contributed significantly to our research work in which we would like to include her as a first author of our manuscript. The main problem is that she doesn't have an affiliation.
Our question is to advise us please under what institution should she be affiliated?
Can we list her as a first author without an affiliation?
What type of institutions other than research centers and universities could generally be listed as an affiliation on a research paper?
Thanks a lot!