In Texas there are quite a number of people with work permits that do not have socials.

If so she can/should apply for a SSN.

And always check social media for red flags and I agree with Vince, always meet a person.  

Typically 75% of rental income can be applied towards your DTI for qualification. 

“A new Michigan law bans many landlords from rejecting tenants based on source of income, like housing vouchers, veterans’ benefits or Social Security.Gov.

The FHA rules/regs (in particular the FHA self-sufficiency test) are applied the same across all markets, and I know for a fact that in rural communities across the country, and big cities that are not particularly desirable places to live, it's not a deal-breaker, I am not commenting on those areas. 

But if they don’t even bother to fill out the forms to apply, or get a basic job to make ends meet, or borrow money from family or friends/ somebody else besides you, then they can’t stay.

Same principles apply - being busy will create opportunity. 

Expand your network, educate potential investors, and leverage social media to increase your reach and influence.

Door knock, cold call/text, mailers, social media, etc.