What are the gen one households finances?
Obv they were struggling awhile back but does the SLC pay well? And even if it does, is it enough for nineteen people?
I assume you mean Gen 2? Since the only main Gen 1 household is Colin & Sophia et al. Going with that:
Sadie and Colby do pretty well. They still have a "normal" amount of children, so no outlandish expenses on that front. It helps that their children don't go to preschool, don't attend extracurriculars, and have been firmly indoctrinated into obeying thy father and thy mother. Colby makes a decent paycheck doing maintenance work for the University of Britechester's ResLife department and Sadie is well practiced at scrimping and saving as someone who went from the second of seventeen straight to being a young married mother in her in laws' home. They took a small hit after their transplant to Britechester because moving is expensive and leaving his parents/siblings/etc behind meant leaving their free babysitters behind too lol. But nothing life-ruining, so they've remained solidly lower-ish-middle-class.
Zeke interned in the office of a local business right after he "graduated" and never left, so nearly ten years on, he's steadily increased the size of his paychecks. He's hardly making the big bucks but it's a decent living, especially when he's A) lacking anything but the most basic education/certifications/credentials and B) a homeowner with C) just two children and D) no childcare costs in E) a low cost of living area. He and Hadley will never be rich, but they do okay. The ISCS community provides them with a strong support system (low-cost babysitting and other services, general favor-trading, etc) which helps them cut down on costs further.
Sam and Maite are probably the worst-off, although that has less to do with Sam's earnings and more to do with their situation. They're currently living in a small, rented, two-bedroom apartment. It suits their needs for now but will be a tight squeeze if they eventually hit 5+ kids. (And they're not using contraceptives, so...) They could probably afford something nicer but Sam's not one to expend money or effort on his wife's comfort; besides, it was the only thing they could get on such short notice after their quickie move/return to Simerica + wedding. He's in the Army Reserve and also works a job in the local corrections system so they have money coming in every two weeks, which is the most important thing.
Cadence and Milo are richhhhhhh rich. I've talked about this before so I'll keep it short: Milo inherited a large house and some cash from his late grandfather; prior to that, he was living at home rent-free. He's also worked for his family's wildly successful manufacturing-type company since he was a teenager and has a nice, cushy, nepotism job. If you noticed it took a while for them to conceive Alexandra, you'd probably guess that they won't be able to hit Colin-and-Sophia numbers of kids. While I can't spoil that I will say that they're the kind of rich that.
Stephen's a college-educated web developer for a local business and is having a great time in his bachelor pad across town. No wife, no kids, no expenses besides the basics. Obviously he's still entry-level right now but right now he's probably the Wagner kid most set up for future career success. Good for him!
Colin and Sophia are very like Michelle and Jim Bob Duggar in that they have several streams of income. Follow The Wagners: yes, it pays well. It's not just the actual money that changes hands but also the bills that SLC foots. Trips, activities, and so on...if it's SLC's idea, production (generally speaking) covers it. All in the service of good TV. Besides that, Colin and Sophia receive modest salaries for their work with the ISCS, and make additional money via smart investments like the rental properties they bought many moons ago. They also haven't been a family of nineteen ever; Sadie moved out a little around nine years ago in-story, before Sabrina and Caitlin were born. And since then several children have moved out (mostly to get married) and/or started contributing to the household in various ways (the boys via part-time jobs, the girls via unpaid childcare and chores). So they're okay!