When you tell the head priestess that she has been rejected by Magran because she sent someone else to do her trial for her, you receive the worst reward. From listening to Durance and everything we've learned about Magran, that is the correct answer. The other answers are merely blowing smoke up her ass which Magran would not appreciate.
At first I loaded and went with one of the fluff answers just to get the better reward but then went back and did it the first way and just decided to eat the negative reputation. It just seems bizarre and frankly wrong that the only Magran quest in defiance bay would reward dishonesty/weakness since everything we hear and know about Magran has her prizing brutal honesty and strength of character over all else.