Mum's been diagnosed back home with lung cancer, with 2 tumours in lung and head that'd been removed, and she'd been treated with radiotherapy on head, which we still don't know if it worked. 

I brought her for cancer treatment, and was giving the information that I knew at the time. Also provided with all the medical records that'd been diagnosed back home. 

It has caused a confusion for doctors, because she had advanced cancer that cannot be cured, that's what I learned later on when we had an appointment with doctors. 

I was told that they can only give her more time with chemo, for what we agreed but mum didn't know and still don't that there's no cure.

It was hard to tell my father "her husband" what was going on, because I was blaming myself for it. I thought it won't take long but it has taken longer than I thought, so I thought her cancer got worse here, but my father said that he heard that already from doctors. When I said does she know? He said that "she knows that it's deadly, and that's all she has to know", because she has hope and that's enough. 

She said the other day that if she wouldn't have come here she would be cured by now, and forgot about it. 

We have an appointment with oncologist next week, where they'll decide if she can go through chemo, because she was weak at last appointment and they couldn't do anything. 

Should I tell her what's going on? If so  should I take the blame so she wouldn't end up being mad at him? They have had a great relationship whole life, and I would rather have myself blamed then they arguing at this point. 

Sorry for messed up message. I missed some info, but ready to provide, if necessary.

Thank you