The only thing I can think of is if they get in trouble as a sexual offender with minor 

Account ClosedHousing discrimination is discrimination based on protected class status, variously including race, gender, religion, ethnicity, age, national origin, sexual orientation and gender identity, marital status, or veteran status, in the realm of housing and real estate.so again, if you make the unmarried couple have 3x each, then the college kids need 3x each, and the married couple needs 3x each... be fair and consistent.

She has shown signs of some physical, sexual or emotional abuse (we are not sure what yet) and I plan to enroll her in play therapy (per recommendations from our friend who is a preschool owner and teacher.)

Our stated criteria:Our Criteria:We do not deny housing for race, color, religion, sex, national origin, handicap, sexual orientation, marital status, or familial status.We do deny housing to individuals: when the application is not complete or accurate where there is no sufficient income/resources to pay rent and livewhere there is poor prior tenancy: evictions, violations, damage to rental property, poorly handled move outs, amounts are still owing to landlords or utilities.Criminal activity is at our discretion depending on severity, number of convictions, and how long ago.

You can't discriminate based on the following characteristics.Fed regulations are race, color, religion, familial status, gender/sexual orientation, & disabilityVirginia regulations are Source of income, Military Status & Elderliness (55 and older)You can always search listings on sites like Zillow, apartments.com, and redfin to find examples of what people are posting out there. 

I approached him after work and tried the soft pitch, let us give you a break on rent, put you in a motel or do something nice in exchange, he suggested I do some sexual things to myself, and stated he knew the law and would be there for six months if he chose and no one was going in.

Have a previous bad actor tenant commit a sexual assault and be sued for ten million?

One turned out to be a sexual offender.

It is usually not worth going after tenants for this but in Texas you can only terminate a lease for military service, family violence, and certain types of sexual crimes without penalty.

The letter listed two main reasons for the brokerage’s decision: NAR policies requiring a fee for the buyer's agent and "a pattern of alleged sexual harassment".