Mine don't seem to be bothered by their larger enclosures. They have their hides, and are fine. I would think your problem is more letting her settle in. Let her be, no touching, handling, or feeding for a week. Also trying to feed to much can stress them out. I would think she is ok eating every two weeks.And feeding in a smaller tub could be part of it. I have one guy we got as an adult, he had been fed live his whole life. The only way he would eat was a live rat, in his 40 gallon tank. He won't eat in a tub. Maybe not enough room to strike? Good luck, and I wouldn't sweat it yet.