Is it generally safe for a single woman to do their laundry there in the middle of the night? Have you had a problem with crime at that time? I work nights and live my life that way even when I'm off work to keep sleep stable.

I feel it is generally safe. I've been there fairly late, and no one has bothered me. Friendly remarks only. No one there who doesn't do business there.

Yes, I would say so. The neighborhood/businesses around the laundromat are very quiet at night and it always feels kind of spooky. I've never felt unsafe at any time of night, and neither has my female roommate.