Poor kids (both of you!). I've seen suggestions here about holding/cuddling them when they're sleepy. Other things you can try if you haven't already:
If she has a favorite treat you're aware of, like a blueberry or a waxworm, you could offer those from your hand, or if you need to start slower, let her see your hand place them near her. Get a tiny bit closer each time, until she will take them from your hand. Just don't overdo the treats.
Wear an old tshirt for at least several hours so it has your scent, and then set it bunched up in the tank where she can lie on it if she chooses to. It may help her associate your scent with comfort.
Try to stop thinking of her as mean, and instead think of her as understandably afraid/untrusting due to her previous situation. You never know what "vibes" they might pick up from you, and if you're tense/nervous when you're trying to handle her, she may be feeling that.
Talk to her whenever you're near, in a calm, soothing way. It may help her get more comfortable with you. Just try to be patient, don't take it personally, and keep trying! :0)