Update

Aria seems to be feeling better; I'm posting on her now. However, it looks like there might be a minor problem with her hard drive. When I run Verify Disk, I get this:

Incorrect size for file 0_data
(It should be 606208 instead of 1116444)
...
Invalid volume free block count
(It should be 7631536 instead of 7631410)
Volume Header needs minor repair
The volume Aria needs to be repaired.

I don't understand the rest of it, but "Aria needs to be repaired" seems clear enough.