Joiya appeared to be a handsome woman, with a friendly, motherly face.
Joiya was not particularly strong in the One Power. Her level of strength is described by "The Wheel of Time Companion" as 28(16) which is a middle level in Aes Sedai hierarchy.
She was held prisoner in the Stone of Tear and questioned by Egwene, Nynaeve al'Meara and Elayne Trakand on the whereabouts of the Black Ajah now. She told them they plan to use Mazrim Taim as a False Dragon and unleash destruction on all the nations but to call himself Rand al'Thor.