You handled that well. Maybe she was "bristling" or maybe it was something else. I'm glad you could ignore it. Or at least I hope you could. I think the message would have been worse if you had seen her and not gone over.
Maybe your wife was actually trying in a really really bad way to make you feel better about your dad's chances? I wouldn't give mentioning your dad's illness a second thought...she's your friend and used to be his daughter in law (for quite a few years), it is completely natural to talk about your father to her. I would be worried if you didn't. But yeah, she's probably self-centered and lacks empathy....or perhaps you'll feel better about the whole interaction if you think that maybe she was struggling so hard not to show her feelings for you that she came across as a little snooty.
In the end, it's not the years in your life that count. It's the life in your years. Abraham Lincoln
It is hard to fail, but it is worse never to have tried to succeed. Theodore Roosevelt
