She was very strong in the One Power by Aes Sedai standards, standing above Elaida a'Roihan in the Power, but lower than Cadsuane Melaidhrin, making her one of the strongest channelers of the White Tower of her time. Cadsuane mentioned that "no one had come to the Tower who could match [her] in a thousand years. No one to match Kerene or Meilyn in almost six hundred." 
In the Wheel of Time Companion her strength level is described as 10(+3), confirming her rank.
Born in 698 NE, she went to the Tower in 714 NE. She spent 7 years as a novice and 6 as Accepted.
A highly respected Aes Sedai, she was also one of the oldest Aes Sedai during the Aiel War, and considerably older than even Cadsuane Melaidhrin. She visited Siuan Sanche and Moiraine Damodred when they are taking babies' names just after the end of the Aiel War. She was one of the original of Tamra Ospenya's Searchers sent out by Tamra Ospenya after Gitara Moroso's Foretelling to find the child who would become the Dragon Reborn. 
She was murdered by the Black Ajah during a return to the Tower some time after Tamra's death. She was supposed to have died in sleep in her bed, but Siuan Sanche was hiding under her bed that night, but Meilyn never came to her quarters. Her death was announced by Chesmal Emry, a known member of the Black Ajah. She was the last of the Searchers to die, leaving only Moiraine Damodred and Siuan Sanche to search for the child.