No she's not. She is aware of Nihilus devouring planets and what not, and states if he keeps eating he will reach the prime power of the tech which at that point rivals "some of the ancient Sith" though I do think in time he eventually will surpass that plateau since she does think Nihilus would eat the galaxy if not stopped and she was aware of Vitiate aka "The true Sith"
__________________ "Vader's pulse and breathing were machine-regulated, so they could not quicken; but something in his chest became more electric around his meetings with the Emperor; he could not say how. A feeling of fullness, of power, of dark and demon mastery -- of secret lusts, unrestrained passion, wild submission -- all these things were in Vader's heart as he neared his Emperor. These things and more."
1. Just because Traya was aware of the 'True Sith' that does not mean she was aware of Nihilus' current power.
2. She merely said in KotOR II:
And another quote was:
She never said she was aware of of Nihilus' current power and his feats. She only said that Nihilus perfected that technique.
__________________ RealistRacism: "Sheevites, much like the Banites, were meant to increase in power with each member. From Lightsnake to Gideon to Azronger, this was supposed to be the case. However, knowledge must've been lost in some kind of Gravid-like incident, as Az turned out to be a mid-tier debater with a sub-par track record, sh!itting all over Tempest's legacy. Sad."