I have to disagree. There is no difference in the words. What is right is good and what is wrong is bad. The Blue Fairy never mentions the people as a whole. Saying the right side might be talking about trying to protect the most people, but that has more to do with saying “right side” then with the words right and good meaning different things. It is more about the sides then anything to do with the word right.
And i think that the Blue Fairy may be a bit shady, but i still think it seems like she is trying to work on the side of the right and the good. And really we haven’t seen her do anything bad or wrong. She wanted Rumpel to not be the dark one because he was going around killing people and she did it not by killing him, but by giving a magic bean to his son so that they could go somewhere non magical together. That seems like a good solution to a very big problem.