If we'd work really hard at it, we could get her to come out from these corners. When she did, she'd be happy, wagging her tail and everything. She has been eating as normal and playing outside.
So for a slight moment I wishfully thought: maybe since she's approaching 2 years old, her puppyness has worn off and this is her real personality. Then, as we talked about it and thought about it and I spoke with a friend who also has 2 dogs, we figured out that more than likely she and Pellet have gotten into it and she's clearly been shown her boundaries.
Tonight she is finally starting to incorporate herself into the family and stopped being much of a loner - but she's sure keeping her distance from Pellet. What's Pellet doing? He's cool as ever, laying by his cage.