I don't see how it could be anybody else. Question-how is her name spelled officially? Billy is a male spelling and Billie is the female spelling. Anybody know?
The reason I commented is because I spoke to someone at CT who clarified the names for me. All were people who had worked at the Terminal. I asked if Billy was a male or female employee because of the spelling. I was told it was a female employee. I was also told that Edward was not shortened because that's how the man was referred to.
Today it is more common to use an i or ie instead of a y, but back then names such as Patty, Jenny, Betty, Billy, Vicky, Cathy, etc. were standard.