She has no one.

Not a con for a father or dead former mentor and most certainly not a man who betrayed her. Bryce betrayed all of them, the unit, the CIA, the country. He didn't pick her in particular to hurt. He went rogue and now he is dead and she does not care because she has no one. No one to love and no one to love her because it isn't an agent's duty to love. One must sacrifice the self for the whole. So she sits in a tiny apartment in Langley and when Graham assigns her the task of locating and eliminating whatever source Bryce sent the mysterious Intersect to she jumps at the chance. Keep the NSA's agent in check and neutralize any potential threat. Simple enough. She'll be back to her despair in a matter of days.