I believe the criteria to go to the head of the line are the criticality of the case and the likelihood of a good outcome, and other facors.
If you are dyin’ fast then you go to head of the line assuming they think you can survive
With CF, she has been on a waiting list for 10 years, since birth, She is 10, not gonna make it to age 12 “adult”
The doctors back the family and say they have a match for her. Assume they know her size and weight and suitability of the transplant for her
Do you want doctors deciding your health care, or judges and bureaucrats?