I think she does really care for me, but thinks our M is over. Is this common?
About as common as it gets... She will probably tell you if she hasn't already, and understand she probably REALLY believe it, that she loves you.
I think they go with the "if you truly love something, you need to let it go" as though they are helping the LBS in some way, while helping themselves.
Anyhow, it ain't over till it's over.
Detach and GAL. You'll need the focus and the energy.