I have recently been through a death in the family. My what i would call her "grandmother in law" who was in my life for 27years, passed away in Feb 09 from stage IV lung cancer. I, and so many others were by here bedside at her last days and her last moment. It is an extremely heart wrenching part of your life and you feel helpless. Hospice is a great place to be, they are trained professionals and the are extremely informative. They will and are able to assist you with any questions, fears that you may have. I would suggest talking directly with the caring hospice nurse to see how your mom is doing, how are her vitals, oxygen level. This will give you an idea if you need to make a trip to see her again. If you feel in your heart that you should be there, than if you can I would suggest to go. That will be the hardest thing to see your mom go thru but you will know that you did what you could to send her home in peace. If you can't make it than just know that she is your mother and she KNOWS you love her with all your heart.
My prayers and thoughts are with you during this time.
Vanessa