River Song: Her Story was a lengthy segment of the final episode of Doctor Who Confidential. It featured Alex Kingston, in character as River Song, narrating a chronological biography of her life. It also featured previously unreleased shots from previous stories, including River as a child escaping the Silent.
Because the segment was not specifically credited, it's hard to know who, exactly, made it. It was likely written by Steven Moffat. It featured no new footage, so it had no director, director of photography or really not much of any crew. Its key creatives were likely Offline Editor John Parker and Edit Assistant George Sabapathy, the people credited with editing When Time Froze as a whole. It's entirely possible that colourist Matt Mullins may have been required to achieve a colour balance on the piece, since it was the combination of many different episodes.