"A ship in port is safe, but this is not what ships are built for"
-Grace Hopper-
She sees the world through innocent eyes. She left her grey, tired life behind and headed for the stars. She is filled with kindness; she saw a man alone, without a home and whose hearts were breaking, and she brought him back to life. She has crossed the very boundary between the universes to save the man she loves. She is young, but has seen so much beauty, so much wonder. He took her hand. He said "Run". And she never looked back.
I have to admit, she was not one of my favourite companions, but hope this showed her character well!
Next: The Master