I've been watching the TV show Game of Thrones. It's set in a strange fantasy land were eunuchs are commonplace. One of the characters Arya Stark is a young girl who dresses travels and acts as a boy.
Most people believe she's a boy but a few realize she's actually a girl. If I met her I'd assume she was a eunuch. It's clear there is no bulge in her pants and she lives in a world where boys are castrated for any number of reasons. So why is Arya Stark never taken to be a eunuch?
I think because all the eunuchs wandering around are parts of certain groups, such as the unsullied. Even Varys is known in Westeros as being very unusual. He comes from across the narrow sea, and is therefore exotic.
The most common reason for being a eunuch in Westeros is because you got caught trying to rape someone. Many in the Night's Watch chose to take the black rather than be executed or castrated.
Arya in the books is still about 10 years old and too young to be a sex offender, or former prisoner. She doesn't look foreign while in her homeland of Westeros. Without that exotic look about her there is simply no reason to assume she is anything other than a boy or a girl.
Oddly, as soon as she crosses the narrow sea she drops the pretext of being a boy and actually takes on the persona of "Cat". She becomes a very feminine waif. The last time we see her, she is being given a new persona by the Faceless Men of a much prettier girl than she really is. (They literally give her someone else's face... like from a corpse.)
I'm sure if she had kept up the pretext of being a boy while across the narrow sea she would have been mistaken for a eunuch.
