I'm so very sorry about your loss.. please accept my most sincere condolenses.
And I'm so sorry you had to go through this experience (and most certainly your mother!). I'm no hospice nurse and cannot offer you resolution or answer those questions that trouble you, but there are many wonderful and qualified hospice nurses here who will surely attempt to put your mind at rest and give you the answers you need.
Again, my condolenses. ((((((((((((((((HUGS))))))))))))))