Rosemary is a young attendant of Queen-in-Waiting Kettricken.
Rosemary is a quiet, sweet girl by all appearances. It is implied that she may not fully understand the nature of her employment.
She was employed by Regal Farseer to keep him informed of the activities of the Queen-in-Waiting. Rosemary's betrayal nearly dooms Kettricken, but thanks to the help of Burrich she is able to escape after King Shrewd is killed.
After Kettricken returns to Buckkeep, Rosemary is eventually forgiven and turned over to Chade Fallstar to train as his new apprentice assassin. Eventually Rosemary becomes the master assassin at Buckkeep.