The whole "everything is canon" thing will never make sense because you will have stories that overlap and can't exist as the same time. Obviously things like Donna's messy origin history is a big example, but also basic things like which Bludhaven introduction is canon. Dixon or Seeley's. Both tell the story of Dick's first time in the city but are very different.
She also enjoyed doing bad things and got off on it too. Maybe murdering a bunch of kids was too far for her, but she did enjoy a lot of the things being a criminal allowed her to do.