The problem is, if she gets an adult transplant and it doesn't work (because it's riskier), that would not just affect her and her family. It would also affect the other patient who would have otherwise gotten the transplant.
Transplanted organs are a scarce resource, and these decisions are often a zero sum game (one patient getting a transplant means that another does not). There is obviously room to debate whether the particular regulations in place should be improved, but that doesn't mean that we should support government bureaucrats overriding the rules that are in place, in order to move a patient up in line because of media and/or political pressure.
I don’t think we’ve established that any such choice in recipients is in play here. Do you have specific information on this case or are you speculating?