The housing discrimination laws cover "familia status" Whether or not they are married or not is none of your concern.  

Another in our group tried one of those religious group coverages but that didn't work out too well for a major expense they incurred.We have self-employed friends who pay $20k a year (familia's plan) & yet others who have been just about bankrupt from medical emergencies.

I rent to anyone without consideration of their familia status, race and other things.