I want to make sure you thoroughly understand this piece since you are going it alone.The Fair Housing Act prohibits discrimination against prospective tenants and current tenants on the basis of the following characteristics or "protected classes": race, color, religion, sex, national origin, disability, and familial status.

They have to meet the definition of disabled, and show a related need for the animal to their disability.  

And the service dogs are only included in a protected class as a reasonable accommodation for a disabled person - so the protected class is a disabled person.So, I don't see any problem with saying yes to one dog, or no to another dog, based on anything you want.  

Sounds like she could lose her job and then they live off his disability and tell you they can no longer afford rent.Based on what you have provided it would be a NO.

The applicant must request a reasonable accommodation to have one, and must meet the requirements as a disabled individual who needs an accommodation based on their disability.  

I'm a low income senior on disability now, and I live in subsidized senior housing.  

Well, I'm now disabled and low income.  

We also don't consider SSI, or Disability, or child support as only means of income...

You know what ended up working for me, is disabling java script on the BP website.  

Here is the Seattle definition: “Discrimination” means any conduct, whether by single act or as part of a practice, the effect of which is to adversely affect or differentiate between or among individuals or groups of individuals, because of race, color, creed, religion, ancestry, national origin, age, sex, marital status, parental status, sexual orientation, gender identity, political ideology, honorably discharged veteran or military status, alternative source of income, participation in a Section 8 or other subsidy program, the presence of any disability, or the use of a service animal by a disabled person.