Wetspot has "escondido" on their list at the moment, so with you in WA, it might work for you, since they are in Portland Oregon, and they ship.
But other vendors may have them too. Both Rapps and Cichlidconnection both have vontehillo.
If I were you I wouldn't get just one female, if you really want a pair, 4 or 5 would be a better bet.
My male variant chairel, is very choosey, and killed a couple others in the tank, before he decided which would be the one to spawn with.
And it just so happened, they've spawned again today.

Females have a dark blotch in the dorsal, that is sometimes obvious, sometimes not.

Note the darkened area in the dorsal of the female above, her profile is less steep than a normal male, and her fins are a bit more rounded, although all these characteristics can be nebulous depending on the individual.
But when not spawning, a male will not have dark in the dorsal, like the one below.
When raising fry the color thing goes out the window, here is my male guarding fry.
Okay, so its pretty much location. I figured that was the case. Its the same with the killifish I was keeping for a while. could be same species, just different locations, different color intensities and we try to keep them separate from others so as to not cross breed. I was told by the original owner that this one that I have is a true escondido. I have so many people refer to it as a texas green and I just dont bother arguing with them. How hard is it to find a true escondido female? I've been looking for 4-5 months now and cant find even a young female. Every one I see is referred to as texas green.
And I was told the one I have is male. How can I know for sure?