I'm so sorry for your terrible loss.
It was a year ago almost to the day, 7/25/12, that my 18 year old niece Shea passed away in her sleep after a 4 year battle with Hodgkins Lymphoma. My sister is still pretty devasted from losing her daughter. Losing a child is the most difficult thing any parent can experience.
I hope your family can stay strong in these difficult times.