well, i think shes dead. and its not because of what kakashi said. it about the leafs lack of kick ass medical ninjas until tsunade and shizune came back. if she were still alive im certain that she would have insured the policy of medical ninjas being in every team would continue to be enforced. which was not the case. being the fourths student, i would think that she would be a kick ass jounin like kakashi, and would have a sufficent impact on the decision of insuring the uprising of great medical ninjas. the fact that we NEVER really seen her only serves to inforce my idea. i am certain that kakashi was exagerating with his statement to sasuke, but i am also 90 percent certain that rin is not the anbu chick and she is dead.

the reason i feel that kakashi exagerated is because the anbu chick (whoever she is) is still alive, and she was most likely a former anbu comrade of kakashis, and we all know that after the obito situation kakashi wouldnt easily allow those comrades to die.