Dory is a very effective force of good that the High Council would very much like to recruit. Unfortunately, despite her great success in aiding Marlin in his quest as well as her capabilities as liaison to the sharks, every time the Council approaches her she accepts a position...and then promptly forgets their existence.
That is, until Dory received a vision to find her family again. It turns out, the council had been doing some research into Dory's situation, and decided to use a vision to bring dory back with her old family. While Dory's memory of the journey is...patchy, one thing does remain constant afterwards. When the council sent Ariel to try contacting her again, they told her about how they helped her find her parents. And in gratitute, Dory swore that she'll give her all to help the Council after that. While some of the council is reluctant to keep her on full time due to her mental health issues, they did give her a duty to keep the reef safe with her friends, as there were rumors of the friends planning to destroy it.