The key term is "given" which implies an external agent was involved. Generally I think people point toward Fate or Destiny. In that case then I agree with you that it's completely counter-intuitive that she was imbued with these powers and subjected to such abuse along the way so that her lesson and conclusion was to never have used the powers she was given. How about not giving her those powers? It's not as if time travel abilities is something you just buy at the local Walmart. And beyond those time travelling what life lessons does an innocent kid have to learn that can't be learned like any other normal person? There is just something sinister in such an agent saying ;

"Here, spend another week with your best friend that you lost contact with who you just saw get killed, oh and watch her die a few more times along the way before you lose her for good, and also whilst you're at it watch another friend of yours try to commit suicide, and have some fun being drugged and abused by your hero teacher too. And just for icing on the cake you can take all that back with those time travel powers you were imbued with, but don't use them. Is that too much for you? It's all cool, it's all good character building because fuck you in particular, Max Caulfield"

This isn't a life lesson, this is cruel and unusual punishment