I finally caught up with her last evening.
She said she heard the murmur when doing an exam, and that it's hard to tell much more about it from that. I informed her that another vet had mentioned it as well, when Har was a puppy-in Vegas. But we had not heard it mentioned since that, so we had hoped she outgrew it. She told me some symptoms to look out for, if it progresses. And that they don't typically treat it with medications until heart failure begins.
It is all very upsetting to me.
She sent me more information, that I'll print & read today. Hopefully being educated about it will empower me, not just scare me even more.
Please keep her in your prayers

Thanks for asking.