i'm so sorry for u and your friend's family.
but u can do nothing.., keep good memories of her and wish her a peaceful rest...
one week ago, one of my friend's friends were died of heart disease. he worked at night in a hospital,when he finished his work and went out, he suddenly collapsed and died (heart stopped working)...
take care of yourelf, our friends, we don't need to sacrifice our lives to make a best living. balance between spirit and physical strengh is important.
when u read ' D'ont move my cheese', don't forget to read ' Stop worrying, start living'. when u read ' The best salesman in the world', don't forget to read ' the importance of living'. when u rush to a business conference or ' business moral promotion meeting', don't forget to take some time to bring your kids and wife to play in park.
when u have no choice before a difficult and demanding job, try to build your family love and friendship. spiritual comfort can soften and relax your pressures.
if there are so many ways to achieve a healthy life, the end is always the same: to train u to have no fear of life, be friendly with your life.