An 85 year old with broken ribs and lung surgery for the removal of metastatic growths is the textbook definition of high risk pneumonia patient. It's pretty much guaranteed in her situation given that deep breathing exercises are used to help prevent pneumonia, which she can't do with broken ribs.
She's cancelling planned events that are still several weeks away. If she were recovering, it would be more of a "wait and see how I feel" type deal as the event draws near. You only cancel things that far ahead of time when you know there is no way you're going to make it….