I'm in the camp that says magic is largely symbolic, so if they said she has to give up part of her name to heal Fenris, then that is what she has to do, whether she really had to do it or not.
Sadly it also means that her name so far should have been translated into Noelle (or Noëlle), to make the change come across as maximally obvious. XD
Nonetheless, thank you for your hard work and the explanatory comments page.