I think her illness affects her mindset and hence the bitterness she is spewing. Death is not far from her.
She has survived now for more than a year after her surgery on May 17th, 2017. The truth is death is not far from ant of us. But not far is of course relative. I see no evidence that she is knocking on the pearly gates to heaven.
It may well be chemo. I have a few friends who tell me they were never the same mentally after they survived (with chemo) life threatening cancer. I don’t think that the medical-industral complex will admit to this.