I think “family” status is usually on the list of bad reasons under the equal protection clause. I’m pretty sure that you can’t bar a mother and child from living in a two-person apartment, for example, unless there are safety concerns for the child that would not apply to an adult. “Kids are noisy and will wake up the people in the apartment below” has been found to be an insufficient reason.
[By the way, welcome back, Jodi! You have been missed.]
Right, EN, but my point is that you can discriminate – using the word in its strictest sense – for legally non-objectionable reasons regardless of whether objectionable, illegal reasons also exist for the discrimination.
For example, if I refuse to hire a woman for a particular job because in my opinion she is not the best candidate for the position, I am discriminating against her for that reason. If she alleges that I refused to hire her solely based on her gender (which is illegal), then my defense will be that, to the contrary, I refused to hire her because I simply did not consider her qualified. Similarly, in this situation, the tenant alleges she was discriminated against because of her marital status. I imagine that the landlord will argue that, to the contrary, she was(or, rather, they were) discriminated against because two people is too many for that small a space.
And thanks. 
That is a tiny apartment. I lived in one only slightly larger (it was 13x20 ft., $265/mo. all bills paid) and when I considered having a friend move in the management told me that the apartment was too small to have 2 people living in it, I would have to move up to a one-bedroom.
MGibson, where in Dallas did you pay that much for an apartment? I know there are some that expensive, but they are pretty upscale for a first apartment. I live in Richardson, about a 1/2 mile north of the Dallas city limits, and my rent for a nice 1400 square foot 3 bedroom, 2 bath apartment with full-sized washer and dryer is only $995 a month. There are apartments to be had for far cheaper, too.
I didn’t pay that much for the apartment itself. But when you add up the cost for moving, setting up utilities under your name for the first time, a deposit, and first months rent it adds up. I lived in far north Dallas, almost in Carrollton, in a 650 sq foot apt. with a stackable w/d for $525 a month.
Marc