You can't take off the UTH and put it under the tub?

I would leave her in the 20L until you have the appropriate heat source for the tub.

As for feeding, I would start her off with some fuzzies and then move up to hoppers. The fuzzies won't hurt her, they barely move and usually don't even have their eyes open. After she's eaten a few of those, I would try to switch to hoppers. I was told to start feeding my baby BP hoppers so I tried that, but she acted like she was terrified of the hopper so I had to remove him and let him free outside lol. I kept her on fuzzies for a while and now she's been chomping hoppers like they're going out of style. She's also finally put on some weight.

I bought her in early May and it's taken her a good 2 months to get used to her surroundings and not be terrified when I walk into the room. She was not CH bred though.

Where did you purchase this snake?