Speaking of siblings in Teen Wolf, I am also very fascinated by the amount of siblings with different last names.
Alan Deaton and Marin Morrell.
Brett Talbot and Lorilee Rohr.
Valerie Clark and Hayden Romero.
And none of these are explained in canon!! Sure, it happens that siblings have different last names. There's usually a reason for that and, as this is a show, you could tell the story of why that is, because it could be an interesting story.
With Deaton and Marin, the most logical conclusion would be marriage. Only that Marin being married begs the question who her spouse is, and where her spouse is. Were they a part of Deucalion's pack? Are they dead now? Why else would they not try to help Marin out of the Alpha Pack? There's a story here that could have been told.
Brett and Lori are baffling, since both are teenagers and both also go to the same school and are in the same pack. Like, if they lived apart, I'd go, oh, yeah, sure, their parents are divorced, mom took her maiden name back and the kid that stayed with her also changed names accordingly, or maybe mom got remarried. But the close proximity and just full lack of giving an explanation leaves that one open too. Again, a story that could have been worth telling, especially as these two are recurring, so why not tell us more about them. This could have been interesting.
The same goes for Valerie and Hayden. Is it a divorced parents kind of last naming? Is Valerie married and we just never meet her spouse at all? Also, what happened to their parents to make Valerie Hayden's legal guardian? There is so much implication here that's just never delivered upon.
As much as I love making up my own headcanons, I also do find it frustrating at times when a show sets up something that has the potential for an interesting story, the potential to flesh out characters and their backgrounds more, and then just... doesn't do anything with it.
