Did she leave immediately following the events of Kotor 2? If not, we could place that in the intervening years.
Even if we set it during the time between KOTOR2 and her departure The Exile can't be the master.
From Wookiepedia:
After the defeat of Traya and the Triumvirate,
Surik returned to Dantooine to complete her retraining as a Jedi. But it was not long before Surik's droid, T3-M4, revealed that he had been carrying information about Revan's fate the entire time he had been in her possession. The droid stubbornly refused to show the information to anyone other than Bastila Shan, and so Surik took the droid to Shan's home on Coruscant. Together, the two watched as T3 revealed that the Ebon Hawk had crashed on the dead planet Nathema, once a member world of the Sith Empire. As they watched, the recording revealed that Revan had been captured by a Sith male—a race thought extinct since the end of the Great Hyperspace War. Unbeknownst to them, this Sith was Lord Scourge.
Recognizing the threat that the individual posed, and spurred on by her continued unpopularity amongst the older and more conservative ranks of both the Republic and the surviving Jedi Order, Surik resolved to rescue Revan from whatever fate had befallen him. Before Surik's departure, Shan revealed that she possessed Revan's mask. She presented it to Surik to return to Revan, in the hope that it would restore his memories and aid in his escape. Leaving her apprentices behind to resurrect the fallen Jedi Order, Surik and T3 boarded the Ebon Hawk and set off for Nathema.