She was plump and motherly with gray hair.
She was Aes Sedai for nearly 200 years.
She became one of the Black Ajah's searchers for the Dragon Reborn, after they found out that he had been born. Her search eventually led her to Kandor, where she crossed paths with Lan Mandragoran and Moiraine. She tried to kill them, and did kill Diryk, prince of Kandor, Brys, the consort and Swordbearer of Queen Ethenielle Cosaru Noramaga of Kandor, and Iselle Arrel, the daughter of Edeyn Arrel, Lan's carneira. When Merean grew overconfident and turned away, Moiraine managed to kill her with a knife in the back after a severe duel with the One Power. To keep the Black Ajah hidden Moiraine burnt Merean's body.
Her name is somewhat of a riddle. Her first name is mirrored in the first Queen of Shienar, Merean Tihomar, but her English-inspired name suggests an Andoran origin. The mystery remains unanswered to this day.