She has big melting brown eyes. She is plump and quite pretty.
Arymilla was one of the nobles who didn't support Morgase Trakand when she assumed the throne after the Succession, and was forced to swear fealty to her afterwards.
Before the siege
Siege of Andor
When both Elenia and Naean are being transported to Aringill, Arymilla's troops help "free" the two women in exchange for them throwing their support behind her claim to the Lion Throne, while being de-facto prisoners. She then musters up all her forces and begins to lay siege on Caemlyn.
She pays some of the mercenaries in Elayne's employ to attack the Far Madding Gate. She mobilizes her entire force and attacks the gate as well. Her army is hit from behind by half of Elayne's force and in the end Arymilla's army surrenders. She is taken prisoner by Elayne.
Elayne eventually releases Arymilla and passes judgement on her crimes against the Crown. She is stripped of all her titles and her lands are forfeited to the Crown. Elayne then plans to give her back land but in Cairhien and not Andor.