They go to the same school as Ron, who says that she likes Will and finds the other two "stuck up." This makes her about the only person who can tell the three siblings apart. If they are siblings.
Little is known about the Golden. They are called that because they use the surname, but also because their skin is a strange golden color. It goes well with their blond hair and gray eyes, but the overall effect is rather unnatural.
Comic books teach us that those who are peculiar looking and mysterious also have special powers, but there is no evidence that this is true of the Golden. Their main goal seems to be to blend in with the other teenagers around them, but they're not very good at it.
The Golden first appeared in "The Golden Mystery," appropriately enough. They are also in the current story, "The Mystery of the Quiet People."
The Golden are somewhat inspired by three characters called The Golden from the late, lamented comic book The Establishment. Those characters are quite different, since the comic-book Golden were very powerful superheroes, quite a bit older than our characters, and they looked similar to each other but not identical.
The comic-book Golden were named Alex, Stuart, and Will, after the actors in the British television show The Champions (who the comic-book characters were somewhat based on). In that show, Alexandra Bastedo, Stuart Damon, and William Gaunt played Sharon Macready, Craig Sterling, and Richard Barrett, so I called my characters Sharon, Craig, and Will (for symmetry it should have been Richard or Rick or Dick, but those didn't seem right so I went with Will).
To go further into pop culture history, the look of The Golden (both groups) were inspired by the children in Village of the Damned, a movie which was based in turn on the book The Midwich Cuckoos, which also influenced the characters The Stepford Cuckoos in the X-Men comics, sisters (originally five, now down to three) who share telepathic powers and, to some extent, a common mind.
However, as I say, all of the characters named above are very powerful, which is apparently not true of The Golden.