What we learn from Penman is that one

Penman tells us herself that she tried to be as historically accurate as possible,and based on this information from her,we can decide how accurate we believe the story to be.What we learn from Penman is that one of the points of writing this story was an effort to debunk what she believes to be a false interpretation of the life of Richard III as told through his enemies (the Tudors).

Based on what we know of her and her work,we can trust that she has done the best she could to be accurate with her information.She is what historians would call "a reliable" reteller of history because she follows what the historians have been putting together for us for centuries.