I got my first ball python today! She is a 1 year old female (or so he said), and is about 20 inches long. Is she undersized or is that about right? I haven't weighed her yet, but she looks ok and he said she eats weekly (f/t). Anyway I could tell right away I was going to have to put some money into her set up. She has no UTH, her water bowl and hide are massive! Below I have some questions, don't worry about answering them all (or add other advice), any help you guys can give is totally helpful!

I get the feeling she'd be better off with a few snug fitting hides not this giant one, are there any commercial ones that your BPs loved at this size?

Should I get her a smaller water dish too or is this one fine?

As for a UTH, is about 30% of the floor space right? That would be the exo terra extra large which is 11x17", the enclosure floor is 31x19, so if I put it to one side that would take up a 3rd of the tank, does that sound right?

She is on aspen right now, but I might change that, is there a substrate you prefer? Why?

I'm getting a probe thermometer and digital thermometer and hygrometer combo as well as he only had one of those stick on hygrometers which I'm going to remove.

I can tell she needs belly heat, she feels like my rescue leopard gecko did when I first got her and all she had was a light, always a little cold to the touch and super super docile and inactive, probably because she wants to soak up some body heat LOL. I'm placing an order today from Pets and Ponds (I'm in Canada), so she'll have to live the way she's been living for a few days more.

Here she is, it's more of a size comparison with her hide and enclosure than to really get a good look at her. Her water dish is about the same size as the hide is.