Brooke (The Lady in the Lake)

Brooke was a clone of River Song and Companion of the Fifth Doctor.

She had been sent on a mission by Madame Kovarian to kill the Doctor and joined him as his travelling companion. (AUDIO: The Furies

She shared numerous adventures with the Doctor prior to their arrival on Terminus Prime. (A Requiem for the Doctor

When River Song summoned the Doctor to Terminus Prime after witnessing the death of what she thought was the last of her siblings, Brooke was present in the TARDIS, leaving River shocked as she didn’t recognise her, assuming the Doctor would be travelling with someone else at the time. (The Lady in the Lake