And this is just your opinion. Wich has the same validity as saying that the moon is made of cheese.
Librarian or not, she did have a lightsaber and knew how to use it. Jedis did have different roles for their members, if you want to call them Jedi Librarian, or Jedi Cook, or Jedi Janitor, that is up to you. Fact is, more than half of what we know about SW universe comes from different sources than the movies.