And here they are, together!
Alvin and Robin look like twin sisters, but one is a robot and the other is the human upon which it was based. Robin is that robot; her name, while also being a portmanteau of "Robot Alvin," stands for "Robotic Operating Bot and Intensive Nurse." Her creators, Maeko and Okeam, haven't quite figured out how to make a synthetic skin suit that's absolutely seamless, so Robby here kind of has a few scars from where they sealed her up.
Bases by blood-cocoa on deviantART