Brother of Potential Renter wants to pay

[David Moore]

I'm showing one of my properties and I've gotten a good response to come see the property.  One guy sounded really impressed with the property, and he was very confident in his credit, telling me he is an electrical engineer.  He says he wants to help his sister, who is divorcing the husband, and needs a place soon for her and the two kids.  I will require both the adults to do the credit check...he doubts her credit is good.  Yet, the brother is convinced he will foot the bill each month.

No matter how well intentioned, 2 or 3 months out, if she isn't getting assistance or looking for work, how can I trust this guy to keep paying the rent?  I know how family relations can sour in a minute.  Have any of you come across a similar circumstance, and can you share how you addressed it?  I have other applicants, but I want to give this guy a fair shake.