So I haven't heard from my apartment manager yet, but I did email the SPD and ask them for advice. I spoke with a very nice officer and she is planning to investigate further as to whether my neighbor is just off her meds or something more serious.
I feel pretty good about this situation in that I think that my neighbor probably just needs some help and now (hopefully) she will get it.
That being said, I am still moving. So keep your eyes peeled for potential Quiana roommates.