Update: I have a strong feeling that she got dumped by OM when she traveled. Some of her behavior soon after she came back is consistent with distress related to the rejection. She is also making some overtures with me and said she wants to talk. She has not stopped being nasty so I told her I can only talk if I feel she is ready to have a reasonable and respectful conversation. She went ballistic. I also don't trust her because I feel she is probably considering this only because she got dumped.
She probably wants to explore piecing but I don't trust her. She has not told me that directly. Would really appreciate any suggestions and advice. Any resources on DB about piecing, like preconditions, if I should even accept, what to look out for if I suspect she is considering piecing etc?