I wouldn't worry about the back thingy...I have all kinds of back pain and I rarely communicate with my WAW. It sounds a bit like stress to me. She did say she was uncomfortable. If mine asked me to come back in the house that would be like inviting me back home. Anyhow, congrats on her bringing up R talk. Just try to listen, validate, and talk much less. Another thing, she might not have wanted to come over and talk about R for any period of time. I'd be thrilled if mine mentioned us. However, you did get the message out. She might ask to talk about R at your place another day. So, for now, I would not be upset by it. Perhaps, I would try other things like meet at other places and such like your x-mas gift exchange...
Heck be happy, once again she contacted you, is thinking of you, and she even has a gift for you.