I don't think I have anything else to add that you've probably not thought of yet but what temperature is the room her cage is in? Is it cool in there? Just wondering if she likes the warmth of her igloo so much that when she comes out she gets cold?
The only other thing I can think of is providing lots of toys and things to do - I know that sometimes a hamster who's cage doesn't have that much in the way of toys, tubes, chew things etc has nothing to come out for. I'm sure you've already provided all this however....
She probably just loves the peace and quite (hmmm, kinda like me...
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