Thanks so much for all the advice again! I went ahead and put a colored mug in there for her, and though she hasn't really explored it too much, it has received at least a cursory acknowledgement. I think she's still getting used to all the space...
Actually, I did buy a pack of the "betta bulbs" at Walmart--they're the little brown rock-looking things at the bottom of the tank.
iamtetsuo, have you ever had any experience with those? The opinions I found online seemed to say that there wasn't 100% germination, but I'd hardly expect that. As long as a few of them root, I figure it'll be good.
I went back after I got off work and ended up with a filter and a heater that are now installed and running nicely. They sure do ugly up a tank fast, don't they? Blegh. And so, I'm going to have my mother order me a tank hood with lights and everything instead.
I'm convinced now that the "betta fish bowl" mythology was created by companies to sell fish. I mean, who would buy one if they knew how much they really ought to be investing in taking care of their fish? Fish were always supposed to be the "cheap" alternative, but I guess that's just the industry talking.