Who is River in Doctor Who?

River Song:

• She is Amy and Rory's daughter.
• She was a time lord, because she was conceived on the TARDIS.
• She was kidnapped as a child and brought up to be the assassin who kills the Doctor.
• She is also the Doctor's wife.
• She both kills the doctor, and saves his life by giving up all of her additional lives (from being a Time Lord).

It's complicated.