She is from Kandor.
Her Saidar strength is given in the WOT Companion as 21(9); she is just strong enough to Travel.
She is black haired with a white streak above her left ear.
Fleeing the Tower Edit
When the Liandrin's group of Black sisters left the White Tower, they took several ter'angreal with them. They first fled to Tear, but they are followed by Elayne Trakand, Egwene al'Vere, and Nynaeve al'Meara. They captured the three pursuing them, but Matrim Cauthon rescued them while he aided Rand al'Thor in taking the Stone of Tear.
Tanchico and Amador Edit
Rianna and the others then fled to Tanchico, but Joiya Byir and Amico Nagoyin were captured. After arriving, they lived in a house that used to belong to a Darkfriend merchant. They then gained access to the Panarch's Palace and held the newly invested Amathera Aelfdene Casmir Lounault captive. Unbeknownst to them, they were followed again by Elayne and Nynaeve, who had been told where they were going by Amico. Elayne and Nynaeve freed Amathera and left as a mob gathered around the palace.
The Last Battle Edit
Regardless of what her task was or if it was completed, Rianna appears again at the Field of Merrilor in Alviarin Freidhen's company. Together with Alviarin and a number of Darkfriend Asha'man, she is lured into an Ogier stedding and taken a captive.