Op, your choice of the word, "refuses" certainly does not make you look good.
OP here. I appreciate everyone's thoughts, especially those that have gone through this, either themselves or a loved one.
To the PP,
she used the word refuses. In all caps in fact. She sent a note saying that she REFUSED to see ANYONE who knew her while she was sick. She said she would be extremely angry if we tried to visit, or if we sent anything at all to the hospital or called her (cards, flowers, notes) after her surgery. If my dad allowed anyone to see her, she would move out and go through treatments on her own. So, she is really adamant about this and I definitely am not interested in countering her wishes. But I am, as my original post pointed out, trying to figure out how to support my dad and what, if anything, to tell the kids. I'm not trying to work around her wishes. I definitely will not visit, call, send things or have the kids be in contact for as long as she wants that. And I hadn't thought about being immuno-compromised, so that's a really good point.
But, I worry still. My dad is almost 80 and 2 years out from his own cancer treatments, so its not like he's in the best of shape to do all the heavy lifting, should it come to that. Perhaps she will be open to a caregiver at some point, but she has indicated so far that she wants no one else in the home. She has long refused to have anyone she does not know in her homes (she does not trust strangers in the home, does her own cleaning, etc). We live across the country so its hard for me to just check in with him and take him to lunch, but I'd like to keep an eye on things if I can.
I think underneath it all she is scared. This week, she sent a couple notes telling me she was angry about all these things either I or my kids did in the past (didn't thank her appropriately for xmas gifts, etc). She's also furious at the doctors (took them longer to dx her than my dad, which she chalks up to being not as important as he is, etc). So, she's scared and mad.