Niobe is the captain of the Logos and widely regarded throughout Matrix canon as the best hovercraft pilot and driver (within the matrix). Niobe used to be in a relationship with Morpheus, however the two parted ways after Morpheus received word from The Oracle that he would be the one to find The One. His obsession with finding The One drove Niobe away and into the arms of Commander of Zion's armed forces, John Lock (aka Deadbolt), however it is insinuated that Niobe still has feelings for Morpheus.
Lock's overbearing desire to keep Niobe safe is what drives her to volunteer the Logos to return to the Matrix, an act that thrusts Niobe into a pivotal role in the war between humans and machines.
Later on, Niobe continues her role as a leader and holds steadfast as one of the biggest allies to Zion in the events of The Matrix Online. She makes it a point to introduce herself to every "redpill" that is freed by a Zion operative.