I'm guessing that they were distant cousins (do we know anything about Joshua's siblings, if any? I don't remember.) Could be the children of a child or grandchild of the original Collins who came over here.
Magnus and Taeylor: I know both those traditions too. When I was little, cousins of my grandmother's were always to be referred to as Uncle and Aunt so and so. Its a matter of respect; kids were expected to show respect to their elders and NEVER to refer to them by first name only. Don't think it's just a southern thing Taeylor. The manners down south are like the ones I was raised with up here. Perhaps because my grandmother was waay older than I, or perhaps because she was English, who knows. My grandmother's generation was the one where people were friends 30-40 years and more and always called each other Mr. or Mrs. So and So. I don't even think I knew the first names of any of my grandmother's friends -- and I probably thougth I'd be struck by lightning if even thought of calling an elder by their first name only.
I know there's a clip from a Fest, I think on the 30th Anniv. tape, that makes me grit my teeth because it's so far to the other extreme that it strikes me as rude. It's a Q & A, little kid about 5 or so is asking a question, when speaking to Selby he calls him by his first name. Just seemed so disrespectful, given how young the child was, and struck me as odd given either the kid or the parent specified being from WV, where people tend to have the Southern/Midwestern politeness.
Jeannie