I got the phone call from nurse Debbie (sirrahbed) and we came to the conclusion that the vet was being extremely cautious and was only talking about the worst case scenario. I looked it up and Cardiomyopathy can only be detected from an ultra sound. I think the vet was basing the possibility on some of Abigails symptoms. The heart murmer would not be related to cardiomyopathy if it exists.
So, she probably doesn't have it but I'm so glad the vet is being extreme just in case it does exist. I would rather be over cautious than miss some small sign of trouble when I could get her help.
So, I will be bringing them home in about an hour. The nursery/recovery cage is all set up. They have Fancy Feast turkey and gravy waiting for them. I will keep a very close eye on them today and tonight especially. I figure Rosce will be cage free in a few hours but I will keep Abigail caged tonight for sure and see how she is doing in the morning. She LOVES her meowmies soft fleece robe so it is folded up in the cage for her. That is the same robe she slept on when I first caught her. It brings her comfort and that will make me feel better.

Ok, I'm extreme and over the top but I love these little stinkers!!!

Thank you guys for all the support. I have been worried about this and Abigail for some time now. Some instinct tells me that she is a happy, silly little kitten, but something is just not completely right with her. I don't know why I feel that way but I do.