I never really saw the Blue Fairy as something evil. I see her more as someone with limits. She is powerful, but her power is limited. She only uses magic for situations that are needed. and in then only when the price is not too high. Her situation with Rumpelstiltskin was not entirely her fault–he is more to blame than her for what happend to Bae. With Dreamy and Nova, she only told what was known to both Fairies and Dwarfs. I don’t agree with her, but it is noted that her intentions were good and were for Nova. As for her and Gepetto, she did not truly know what would happen to Pinocchio–she could only help so far.