Staying on the cold side

[Brently]

So my girl Athena seems to always stay on the cool side. She really only goes to the hot side after I handle her and put her back in. I keep the hot side at about 88-90 and the cool side is around 78. I am having a problem with humidity but I am about to add a humidifier to fix that. Right now I am keeping her on aspen bedding but plan on changing that to zoo med cypress forest floor. She likes to burry herself in the bedding at night and then will stay there all day and not move. Kinda wondering if this is normal behaviour for a young boa?