Have you tried picking her up in a pillowcase (or reptile bag if you have one) and then inverting it as you scoop her up so that she's covered? My BP is not shy at all about handling but knowing how much BPs like to be hidden and physically covered, I'd think that might help. That way you can also just tie it up securely and have her be in darkness while she's out of her tub, which may make her feel less anxious about being moved. Also it will keep her from biting you. Just a suggestion, not 100% sure if it will work since my baby is pretty bold and I don't have experience with timid BPs.