[Spoilers] "Mi6 AGENTS" on YouTube

Quote :

Likewise, neither Miranda Frost nor Craig Mitchell were ever Double-Oh Agents. Miranda Frost approached MI6 willing to inform of Gustav Graves' operations, but she was never treated as anything other than a source. Her intelligence was so good (because she was working for Graves the entire time) that was was promoted to become Bond's handler in the field. And while she does show a willingness to kill, she never held Double-Oh status.

As much as it pains me to reveal I know Die Another Day's dialogue by memory, that's not Frost's backstory at all. She spent several years in Cryptology (a department/area of expertise within the SIS) and then volunteered for the operation with Graves.