Originally posted by Beniboybling
How did you reach that conclusion?
Well at first we have this observation:
"You have almost completely restored your connection to the Force, but there are hollow places, places that echo within you still."
- Zez-Kai Ell, Knights of the Old Republic II: The Sith Lords
So the Exile as of the Jedi Enclave meeting was considered to still be restoring her connection to the Force, Darth Traya then intervenes and butchers all 3(4) of them through complete Force domination.
Then we have this statement:
Although Traya was more powerful, the Exile managed to defeat her in combat.
- The Complete Star Wars Encyclopedia
So yes Traya as of their battle over a geyser of dark side energy, was more powerful. It must be observed that Traya at her most powerful and with a ton of prep time, was incapable of overwhelming Meetra with the Force, otherwise she would have won this contest.
Evidence for this can be analysed here:
Traya uses vast telekinetic powers to wield a trio of lightsabers against her.
- Knights of the Old Republic Campaign Guide
Force Wave can stun Kreia's floating lightsabers.
- Knights of the Old Republic II: The Sith Lords: Prima Official Game Guide
So Traya's vast display of telekinetic grip can be, at least temporarily, rendered inert. A very impressive display of Meetra's telekinesis given what Traya herself has done:
Such exceedingly powerful displays of telekinetic domination, yet the Exile was evidently able to defeat the Sith regardless.
This is what is stated by the Sith Lord:
"I do not see as she does, but I know that in time, you will come to surpass her power."
- Darth Sion, Knights of the Old Republic II: The Sith Lords
This has quite some merit, as Meetra Surik defeats Darth Traya years before her prime:
Meanwhile, the Exile trained new Jedi recruits, forming a council of her companions who achieved mastery and welcoming others who came out of hiding. After years of slow but steady growth, the reborn Jedi Order made a triumphant return to its long-abandoned temple on Coruscant. But the Jedi Exile could not forget Darth Traya’s final warning, suggesting that evil remained in the Unknown Regions. With the Jedi Order flourishing, the Exile left the known galaxy to follow her former commander Revan into darkness.
- The Old Republic Galactic History 83: The Republic Rebuilds
So over-all we see that the Jedi Exile Meetra Surik was able to hold her own against Traya's powers in a massive geyser of dark side energy and defeat the Triumvirate leader, then spends the next years growing and reviving the Jedi Order under her leadership. Time in which Darth Sion states Meetra Surik will surpass Darth Traya.