Here's a peek at some of the recently-worn outfits in which Geneva has been called a boy.
Perhaps the average stranger's reasoning goes something like this:
1) If you are wearing anything with pant legs, you are a boy.
2) If your clothing contains any "male" colors, like blue or tan, you are a boy.
3) If you are wearing a collar, you are a boy.
4) If you are not entirely saturated in pink, you are a boy.
5) If you are a girl, you are a boy.
More likely, the average stranger isn't wasting a lot of brainpower on the subject, which is fine. It's good for a laugh anyway.