In detail
This is an honest “we do not know”, and here that is the most useful answer available.
The five options the High Commission's document gives for proof of profession are: government employee, private employee, self-employed, student, and retired government employee. There is no separate option for homemakers, the unemployed, freelancers or people working in the informal sector.
Blogs offer various suggestions for these cases: submitting a spouse's or guardian's papers, or swearing an affidavit. None of these appear in the official document, so we will not present them as rules. Better to find out than to lose a day acting on bad advice.
The one reliable route here is to ask at the application centre directly, or check IVAC's own page.