What is the prognosis of a child diagnosed with aml leukemia m4 her WBC was 280000 when diagnosed she passed away but I have so many questions?

Many variables. First, let me extend my condolences on the loss of your daughter. This is clearly the worst thing that can happen to a parent. There are many factors that influence the likelihood that a child diagnosed with AML will survive. The best person to get answers from regarding your daughter's case is her oncologist. I'm sure he or she would be happy to meet with you and try to answer your questions.
I am so sorry. I too have lost a son and have many questions. Believe me - there are no adequate answers. AML is a horrible disease. Rarely is there good outcome. Rarely is there reason or cause. Rarely is there cure. Many present so severe no treatment would be adequate. This was probably true in her case. Write down your questions and go to her doctor and request a long talk. You should get answers.
AML. I am very sorry about your loss. Unfortunately, AML is a very serious disease and some children diagnosed with this type of leukemia die very early during the treatment. Please talk to a doctor you trust about the questions you have.