I can't really remember when I first used shy-twinee as a username, but it had to be some time in highschool. I coined it based on:
every since I was little, I have been a shy gal
I have an identical twin and the school guidance counselor, like most people, couldn't tell us apart so she would often call us twinny when only referring to one of us (I like spelling it as twinee) and the nickname just grew on me.