Let's make her a DBee, but really close to human except seemingly ageless.
For relationships, I'll describe her for the rest of you, and maybe we can figure that out when we all have PCs fleshed out.
Cassiopeia Canon was blown into Earth, during an operation against the Splugorth colony on her world. The resulting rift sucked her into the ocean off of North America, where she was forced to swim for shore. A running fight against a tribe of cannibals consumed the next four days, and when she arrived in what passed for a city, she was exhausted, confused, and half dead. She was nursed back to health and joined the tutelage of Lord Coake in his battle against the Coalition States.
Now, years later, she has left for Castle Refuge, and seeks to spread the Code of Chivalry against the encroaching forces that seem destined to overwhelm the fragile Earth.