Takima has long black hair and an ivory complexion. She is a tiny, bird-like woman almost as short at Nisao Dachen. However small, quiet and observant by nature, she can still be forceful if she wishes. 
Strength and Abilities
Being a Sitter in the Hall means that Takima is also a high ranking sister and a strong channeler by Aes Sedai standards. Thus she has the strength needed to use the travel weave.
This is not confirmed by "The Wheel of Time Companion" where her level of strength is described only as 23(11). But this is probably a mistake because ten levels below the strongest Sitters would mean that Takima is a too weak Sitter compared to them.
Takima's true level of strength can be guessed by the time she spent as Novice and Accepted which was in total fifteen years, roughly the same as sisters that are around level 18(6), in fact the time spent in training usually reflects the strength of an Aes Sedai.
Takima has a formidable memory, she remembers everything she reads and is well versed in the history of the White Tower, Aes Sedai, and Tower law. In fact she was for a long time a teacher in this matters. Takima could recognize one of her pupils at a hundred paces.
Takima is 156 years old, she was born in the year 844 NE in the Mountains of Mist and went to the Tower in 858 NE. After spending nine years as Novice and six as Accepted she was raised to the shawl in the year 874 NE.
She was elected Sitter in the Hall recently in the year 991 NE.
Her Ajah Head sent her to the rebels because she was not invited to the vote to depose Siuan and raise Elaida. This would help keep her safe, and allow the Ajahs to help defuse the rebellion. She has allied herself with the Salidar Aes Sedai and is a Sitter in the Salidar Hall. She supported Lelaine because it would help stalemate Romanda and make the rebellion easier to control.
She reinforces Egwene al'Vere's comments on the Law of War. She votes NO on the Rebel Aes Sedai declaring war on Elaida do Avriny a'Roihan and is outvoted. She weeps when Egwene tells the Hall that the Siege of Tar Valon begins in a month.
She is part of the group that negotiate with the White Tower Aes Sedai in Darein. She is one of the Sitters to re-swear the Three Oaths on the Oath Rod and prove that she is not Black Ajah. She is then part of the unanimous vote to attack the White Tower with their army.
The White Tower re-united
Takima remains a Sitter when the Hall of the Tower is re-united after the White Tower Schism. The Sitters try to hold a secret meeting without Egwene, discussing ways temper the Amyrlin's power when a declaration of war is called. Takima voted against a proposal that would allow only Egwene to deal with the monarchy of the world, which includes Rand as he is King of Illian, while the Hall would take over prosecution of the war and deal with Gareth Bryne's army. In that same meeting, Takima voted in favour of the new rules and procedures in the Hall, which included temporarily replacing a Sitter when she is absent from the Hall and that no meeting of the Hall can commence without all Sitters and the Amyrlin Seat being present.
During the Last Battle Takima, Varilin, and Saroiya are the three Sitters designated to manage the White Tower and Tar Valon in the absence of the Amyrlin, the Keeper and the other Sitters in the Hall.