Jesse is 5' 11" tall and wiry, resembling a sparrow, but she is much stronger physically than she looks. Her hair is grey with a little black, her eyes are small and dark.
She has a habit of tilting her head to one side when she is studying something in front of her, and a habit of tapping two or three fingers on her lips while thinking. She is very intent on whatever she focused on; some people think she focused so intently as not to notice other things around her, but they are mistaken.
She is a very forceful woman, especially for a Brown.
Strength and Abilities
Being a former Sitter in the Hall and Ajah Head means that Jesse is also a high ranking sister and a strong channeller by Aes Sedai standards. Thus she has the strength needed to use the Travel weave to open a gateway unaided. Also that she is a very influential and knowledgeable sister.
Her strength level is described by "The Wheel of Time Companion" as 21(9), not very high for a former Sitter in the Aes Sedai hierarchy. This can be either a mistake (because eight levels below the strongest Sitters would mean that Jesse was a too weak Sitter compared to them) or Jesse can compensate her lacking of strength with some particular Talent, ability or skill (as in the case of Suana Dragand). However, the time spent in training, a total of 21 years, may suggest that 21(9) is her true level of strength.
Jesse is 248 years old. She was born in the year 752 NE and went to the Tower in 768 NE. After spending eleven years as novice and ten as Accepted she was raised to the shawl in the year 789 NE. She was elected Sitter in the year 905 NE until 927 NE and later served as head of the Brown Ajah Council.
Jesse is one of a few characters who are definitely identified early as not Darkfriends, because Alviarin Freidhen has stated that Galina Casban was the only Ajah Head to be a member of the Black Ajah.
Later it is revealed that when Elaida's coup deposed Siuan and the rebels escaped to Salidar, the Ajah Heads were caught by surprise, nevertheless they decided to take advantage from the situation, so they decided to intervene and to take it upon themselves to rule, as had happened in the past, and to bring the Rebel Aes Sedai back into the fold.
It was Jesse herself to suggest the so called Too Young Sitters conspiracy. In fact, following the split in the Tower, Jesse suggests to Adelorna, Ferane, Serancha and Suana to sent the youngest Sitters of their own Ajahs to the rebels in an attempt to control them and bring about a reunification of the Tower. To temporarily replace these Sitters, they choose young sisters whom they think they can control or, in the cases of Suana and Ferane, to replace the other Sitters themselves.
After Elaida was captured by the Seanchan, they acknowledged to one another that their plans had backfired. Furthermore, they also decided the Tower needed a strong, capable Amyrlin, and agreed on Egwene al'Vere, thus ending the White Tower Schism.