She's seems to fine now actually. I guess it was just one of those things where you get worse before you get better.
There's one other swordtail, and a few mollies. There's also neon tetras, corydoras, and ottos.
Tank paramaters:
Ammonia - 0 mg/L
Nitrite - 0 mg/L
Nitrate - 10 mg/L
pH - 7.6...