I would say that she was courageous.    She is an example of determination, truth and class.
She accepted the appointment and agreed to follow the rules set forth.  
When accepting,  she publicly stated that she will do her very best to accomplish the goals of the commission.  She did just that. 
She also said  "When I accepted my appointment to the Commission in 2014 I said publicly that if I found what was happening behind closed doors was in conflict with what was being said to the public I would not remain," she states. "This point has come. I feel I have no choice but to resign if I am to retain my integrity." 

There is a difference between being a thorn and allowing herself to be used to give false credibility and legitimacy to clerics who obstruct progress in keeping children safe.
I am pretty sure Marie did not agree to be on the commission because of a desire for future sainthood.  She wanted to protect children.