Tenant screening with child support

[Raghavendra Jakkani]

For my very first rental property the very first application I got had income which is 4.7 times rent. rent is $2550 and income $12k out of which $3kis child support.  Credit history is excellent. No criminal or eviction record. Even if I go by 3X applicant meets the rental criteria. 

1. I am here for experts opinion to find out what you guys think? Is there anything that I need to consider given this information?

2. Do I need to ask for screening of every one living or only persons signing the lease? The number of occupants listed in application is 3

Rental screening is through Zillow Rental Manager.