You have a great credit score. 

If everything else checks out (credit, talked to her employer, background check, etc), I would try to validate the story with the landlord.

I personally used business credit cards to BRRRR a deal—no money came out of my pocket.

You can work with a local credit union that does HELOCs, Home Equity Lines of Credit or Loans, on investment property.

The credit cards can be stifling, but in the grand scheme of things, $40K isn't a ridiculous amount.

Conclusion: Don´t give your credit card infos for "free" products!!!

Hey Patrick, Do you have a US credit score or do you have credit in Canada?

If It is a wholesale DSCR lender that also does TRID loans, they might require a bit more paperwork, such as a VOM, mortgage statements for properties currently owned, and credit supplements on mortgages on your credit report.

I don't take credit cards but I believe stripe does.   

Run a credit check, which will include her address history and the dates she lived at each one.