River

River Tam was the younger sister of Dr. Simon Tam on the series Firefly. She was a prodigy, and was sent to a private school which turned out to be a government experiment in creating the perfect assassin. After decoding a secret message she sent to him, Simon rescued her, and they both became fugitives. They took refuge on Serenity, with Simon becoming the ship's medic. Due to the experimentation on her mind, River had violent outbursts of emotion and psychic abilities. She was also incredibly skilled in hand to hand combat, performing in ways that no normal human could. 

River Song was a character in the modern version of Doctor Who. River was actually named Melody Pond, and was the daughter of Amelia Pond and Rory Williams. Melody's name was translated to River Song by Lorna Bucket of the Gamma Forest. Pond wasn't translatable because the only water in the forest was the river. River was kidnapped as an infant and trained to kill the Doctor. She escaped and grew up alongside her parents as their childhood friend. She and the Doctor kept meeting each other out of order, and she kept a journal of their meetings. She spent much of her time in prison, which she routinely escaped from and returned to. She was imprisoned for killing the Doctor, although it ended up being just a replica of him. The first time the Doctor met her was when she died, having sacrificed herself to save others trapped in a Library computer. The Doctor saved her by transferring her consciousness to the computer where she was able to live forever in a simulation. 

In 2011, River ranked at #424 for boys, and was #913 for girls.