Kibeth was one of the original Nine Bright Shiners who was there at the beginning, and one of the Seven who agreed to create the Charter. Her power was channelled into the Charter but she wasn't consumed by it - her power didn't go into the Great Bloodlines (the only one not to be consumed, except for Astarael).
As a Bell
Kibeth, or the "Walker", is a bell that controls movement. It is able to give and take away the freedom of movement from its target, or in careless hands, its user. Kibeth has a cheerful dancing' tune, and has the second effect of of making spirits go into, farther in, and out of Death. Kibeth tends to be rung using two hands in an odd figure of eight, as shown in this excerpt from? Sabriel:
Sabriel took up a careful stance, with the bell held in a curious two-handed grip. Kibeth seemed almost to twitch in her hands, but she controlled it, swinging it backwards, forwards, and then in a sort of odd figure eight. The sounds, all from the one bell, were very different to each other, but they made a little marching tune, a dancing song, a parade.
As a Free Magic Being (Or as the Disreputable Dog)
'As I did then, so do I now," said the Disreputable Dog. "I am Kibeth, and I stand against you." ' - Abhorsen
Kibeth wasn't consumed in the construction of the Charter, but rather her mind was preserved as a soapstone statue of a dog. She was kept hidden (and protected) in the Great Library of the Clayr, in the Moon Room (just off of the Sun Room). It was the only statue occupying the seven plinths (most likely referring to the Seven who created the Charter) beside the Crystal crypt entombing a Stilken. She was found by Lirael (in Lirael - book two) and became her comfort toy. Eventually she decided to make a Charter Sending of a Dog, basing it on the Statue but something went wrong in the spell - she kept the statue in her lap and the spell ran out of her control - she cast marks she didn't know and invoked Free Magic:
But still the Charter marks roared through her mind. She had long lost track of where she was up to, or which marks were next-and the golden light was too bright for her to see how much of the sending was done. Yet the marks flowed on. Lirael realized that not only did she not know which mark she was up to -she didn't even know the marks that were passing through her head! Strange, unknown marks were pouring out of her into the sending. Powerful marks that rocked her body as they left, forcing everything else out of her mind with the urgency of their passage. Desperately, Lirael tried to open her eyes, to see what the marks were doing-but the glow was blinding now, and hot. She tried to stand up, to direct the flow of marks into the wall or ceiling. But her body seemed disconnected from her brain. She could feel everything, but her legs and arms wouldn't move, just as if she were trying to wake herself from the end of a dream. Still the marks came, and then Lirael's nostrils caught the terrible, unmistakable reek of Free Magic, and she knew something had gone terribly, horribly wrong.
The Dog drew breath and howled again. The assassin dropped his crossbow so he could jam his fingers in his ears. But even then he couldn't block out the terrible sound, and his legs moved of their own accord, stepping out into space. ... "I made him walk," growled the Dog, sitting back on her haunches, a ridge of hair along her back stiff and angry.
The Dog refused to admit her true heritage, and even would not appear to anyone but Lirael (until she meets Prince Sameth). It isn't until the final binding of Orannis that the Disreputable Dog confesses who she is and uses her power as part of the new seven. Her strength, though, is just as diluted as the Great Bloodline's.
WARNING: Ending of the Book Revealed Below: When Lirael uses Sameth's newly forged sword (it contained the power of the seven bells) to split Orannis into two, Orannis invades her body trying to kill her. In her fear, she calls out the dog's name. The Disreputable Dog comes to her rescue and bites of her hand where she had concentrated Orannis's power, thereby absorbing Orannis' destructive into herself.
"Dog!" screamed Lirael instinctively, not knowing what she said, pain and fear overwhelming her intention to simply die. Again she tried to open her hand, but her fingers were welded to the metal, and Orannis was in her blood, spreading through to consume her in its final fire. Then the Dog's teeth suddenly closed on Lirael's wrist. There was a new pain, but a clean one, sharp and sudden. Orannis was gone from her, as was the fire that threatened to destroy her. A moment later, Lirael realized that the Dog had bitten off her hand. All that remained free of Orannis's vengeful power was directed at the Disreputable Dog.
The Dog then aged rapidly, with a white muzzle and loose skin. She moves into Death after an emotional farewell to Lirael, leaving Lirael alone with a Soapstone Stauette. She then sends Nick back into life, breaking the rules of Death (according to Kibeth). After ensuring that everyone is okay, she moves along the border of death, to seek her next challenge:
Then she wandered off, following a zigzag path along the border between Life and Death, her tail wagging so hard, the tip of it beat the river into a froth behind her.
End of Spoilers