In the army of ghosts/doomsday Freema plays Adeola, Martha’s cousin
I don’t know about greatest, but if you want to read a good novel with Ten in it, Martha in the Mirror and The Ghosts of India are really good!
I know - especially with Ten - there are a few where it really is him but a lot of the time it’s just a random guy with brown hair
Has to be River being Amy and Rory’s daughter