This happened to my brother and his wife. They moved, but it didn't turn out well. They got married young-ish, with only a few years of college. He had more of a hands-on/ blue-collar type of job, but was vested, and it was with a good company, so he was doing okay for his age. She had an office job with no upward mobility. They had my niece, and he sent the wife back to school. The plan was for him to go back later, but, when it comes to work, he's more of a 'traditional' man, in the sense that he prefers to work with his hands in some capacity.
The wife graduated, and my mom got her a job at a major investment house. She got promoted a few times, and they wanted her to relocate, all expenses paid, housing subsidy, etc. When they presented the idea to us (me and my mom) we were shocked at the suddenness, but they seemed like they were on the same page and excited about the prospect of moving out of their hometown.
We, on the other hand, considered what they'd be giving up. His company had nowhere to relocate my brother in that town, so he'd have to start all over, which he seemed cool with.
We were the ones that didn't like the power differential that would automatically present itself under these circumstances.
The thing is, she had always made more money, but he had always totally handled everything else for her, including the house and their daughter. Which
sounds bad, but she had been raised in near servitude, and didn't know anything about kids, so, suffice it to say, she had emotional issues. Meanwhile, he had basically raised me while my mom was working. End result, my mom and I are closer to her than her own mother.
We picked her up from half days, she stayed with
us every summer,
we paid for dance/ music lessons, all with no help from the other grandparents, even though they're in the same damn borough and have plenty of disposable income. They didn't even know she could sing, smdh, but they sure are mighty willing to show her off.
All this back story is important, because it influenced what happened next. So, they move, and everything seems all good to us. A few years later, she's offered another opportunity to relocate, and they move again. A year or so passes, and my brother calls to wish me a happy b-day, and is like, I have something to tell you, but I don't want to ruin your day. Poor thing, I already knew, in my heart, what he was gonna say.
He had caught her cheating. Apparently, unbeknownst to us, she had cheated on him in the first town they moved to, and he had busted her then, but they reconciled. She claimed it was over, and he took her back for the sake of my then- 9/10 yo niece. He's big on family and thought the marriage was worth trying to save, especially since they had been together since they were teenagers. They decided to move and make a fresh start (the 2nd move), but about a year after they got down there, he found out that she was still texting old dude, in a way he found inappropriate. He didn't tell me exactly what cuz he's kinda taciturn, but I can imagine it was bad.
With that, he was done. He started sleeping on the couch and never went back. Although he wanted to move, because he made so much less than her,
but had always contributed his fair share to the household, he didn't have much personal savings, so it took him a few months and that's when he called me.
He's now with some new chick, and says he's never been this happy in his life. She's my age (over a decade younger than he is), wants more kids (which my SIL refused to do), and fills him with such joy, I can't recall him sounding this happy since he was in HS. Also, they have more in common culturally. And my niece absolutely loves her, and her kids (she's divorced). Meanwhile, my SIL is stomping around the house mad and yelling at my niece for nothing, why? Because, apparently, old dude ain't calling like he used to.
I'm telling all my family business like this, lol, because I want OP to tell this story to her friend, and to ask her to consider the power differential in their relationship, if it exists, and to decide if they think they can withstand the inevitable shift. Are their goals aligned? Does he have plans to 'get on her level'? If not, they may be setting themselves up for an unavoidable clash sometime in the future. The way I see it with my brother, their goals were aligned initially, but then they grew apart. She started 'smelling herself', and he was going along, doing the same thing he'd always done, which was suddenly not good enough for her. Caution your friend against this potential outcome.
I have to stop writing these long-@ss posts.