I can't thank everyone enough! It's relieving to know we're on the right track and have already started taking steps to correct the areas we're lacking in. A hydrofarm thermostat has been ordered and we'll be heading to WalMart later tonight for an indoor/outdoor thermometer.
Thanks for pointing me toward the tank set up thread, thejennabird. I wasn't aware there was a tank guide in the husbandry section and that one has a lot of good information in it!
Lucy ate her mouse today inside her habitat and though it took her a little while to wake up and grab it (she was sleeping in her hide when we brought her the mouse), she had no trouble getting it down. I feel much more comfortable feeding her this way; I was afraid she would regurgitate her hopper last week when we used a feeding tub.
I've reread the tank guide several times, and though the higher priced accessories aren't an option at the moment, I will work on some of the other things mentioned in the tutorial as far as set up, positioning, and layout in a day or two once Lucy has had a chance to get her mouse comfortably digested.
Thank you all so much for the quick responses! I apologize if my concerns seem basic and amateur, but I wanted to make sure we were doing right by this pretty little snake.