Again, where does your mother live? If she lives in the NYC metro area, then the odds are she’ll know considerably more gay males than someone who doesn’t live in that area or a similar large metro area.
Many, if not most gays from the sticks tend to go to the big city once they are of age.
One thing you shouldn't forget, however, is that Americans in general are clustered around larger metro areas, albeit not to the extent that you have in Australia, Argentina, or the UK.