My spouse Head Canon takes into account IRL restrictions of game creation as well as in-game RPG and imagination elements, which are encouraged by the design of Stardew Valley.
Nobody's gonna leave the Valley, so those who express a wanderlust are clearly not going to exit, never to return. A character does this in
My Time at Portia and it's a source of annoyance as he's a romanceable character with his own side-quests. Didn't take advantage of that before he leaves? Too bad. I didn't. Oops. Even worse is the character designs in that game leave something to be desired, and this character has IMO the best in the game. Sigh.
An unspoken premise of SDV is that everyone will almost always be available (though not always at their
work counters 
), so even if Sebastian was away on a cruise or Harvey on a flight, this would break some of the game expectations a bit. The best in-game corollary to this is Emily
visiting Sandy on her birthday, but this only happens once a year. And there is the issue of how to "disappear" that NPC for the day/evening in a clean way. I haven't seen Emily do this, so I don't know how seamless it is in-game (and I just missed it in-game, dagnabbit!!!).
These are still functional game design issues, however, and at this point they will not be changed. Late game added one spouse event in v1.4 which was nice, but has mostly continued to add Farmer-focused content, in fact pushing the player physically away from their spouse in v1.5, which I'm still a bit less happy with.
Perhaps this is a mild push that the Farmer should continue to pursue their interests while the spouse can continue to do theirs. Seb can use his bike, Harvey can take flying lessons, Penny can continue to teach the kids. Haley can... make the farm look cute. That's important, right?
Sorry, digressed a bit there. It was always my impression that Maru is still working 2x a week, Penny 3x a week, Sam 2x, Emily every day (heck, she still cooks meals for
Haley every Monday), Harvey every day (? not married to him yet), Seb whenever he needs to, Leah still creates, Elliot still writes.
Shane perhaps gets the short end of the stick as he lost his job, but if he finds focus with the Farmer and taking care of Charlie and the other animals on the farm, then he seems to be in a good place. His dialog at other events indicates he's an animal person, so the RPG Farmer married to Shane would definitely set up at least a Coop and a Barn for him. Abby, Haley and Alex have the least focus in the game. I've married Abby and Haley so far and Haley is quite content to keep the Farmhouse up and does head into town from time to time. She seems to be content. From what I've read of Alex, he ends up in a similar content space, having started the game with the most unrealistic of dreams of anyone, and realizing just that over time.
Yeah, but Abby. I'm married to her in my mangled save which I still haven't sorted out, and she seems into Farm life and also shows up in places on the Map which indicate she's following some of her dreams, but I didn't find her to be quite an enthusiastic spouse. Not the best fit for the role. However this is clouded by poor memory and when I tire of my current saves, I will fix my mess of her save to revisit that experience.
Oh look I rambled, what a surprise.
she is doing college, living with a strict kinda stuck in his ways Father (maybe) and a Mom that doesn't get her darker pursuits. So she doesn't really know who she has yet to be, only that she likes swinging a sword and the Spirit world .So when the farmer shows up she is introduced to more of life than before. What I'm saying is, her dream is to adventure and she does it. Other than that she hangs out at her dads shop, she hangs out with her boys at the saloon and still plays music by the lake/on the farm. She helps with the flies in the farmhouse (I think she eats them) she waters, fixes fences and fills "Miso's" water bowl She never complains (when I was married to Leah she complains about having to do stuff around the house every now and then). I've met Abbyin the hard style mines just recently so I know she is definitely killing monsters. We have a diviner's room in the farmhouse so yeah we're still doing that too. 
