My historicals are 9 most of the year, but in spring they each turn 10 for most of the summer, then go back to 9. Marisol, on the other hand, is 10 all the time. My AGOTs ages are based on the books they were named after: Chiyo is 8, the age she was when she was sold to the okiya and became a maid to the older geisha and Morgaine is 11, the age she was when she was taken to the isle of Avalon to begin her training as a Priestess.

Basically by the books, lol