How can hospice be so certain a person only has two weeks or a month left?

My mother developed aspiration pneumonia in the nursing home and was taken to the hospital. I OK’d the use of antibiotics but now that she is back at the home, we have had to have hospice step in. She is not responsive, not eating, taking in very little liquid (a tsp a few times a day) and no more antibiotics. She is on Morphine now. It was a shock to me that they can so matter of factly predict her death. It seems so cold to me. She turns 93 tomorrow. I feel on the cusp of breaking down. I’ve been through the death of so many— family, son, husband, but they were sudden. This drawn out suffering is so difficult to watch. OK, maybe on morphine, she is not suffering? How do you even know? I seem to be the only one that even noticed she occasionally stops breathing. I called it to their attention at the home and it was, "Oh! Well, we will start counting her breaths." She is transitioning, they said. Even before she was taken to the hospital I was the only one that insisted something wasn’t ‘right’. They finally decided I was right and called for an ambulance. Why am I the only one noticing these things!!??

How long can my mother live like this?

That is my question of the day.