Alright, put that aside for the moment. Why those concerns at all? What's the single thing that unifies them but not other things like agriculture (your city needs to eat) or technology (you need to know how to build it) or... entertainment, say, luxury, everything people spend their money on beyond subsistence? Maybe that's counted as wealth; it's easy to argue that any of these things is either very narrow or very broad, except possibly trade. But then, you could also argue that the object of trade is wealth. And you can't get far without specialization, which is a form of exchange of value even if it isn't formal, so really trade is everywhere.
...anyway. What's common to these four things? How could you express them with a single concept? (Ignoring for the moment the obvious question of why, if you could do that, you would list four things to begin with.)
Can one of them substitute for another? Wealth and trade are linked. Wealth is, arguably, value-to-you as enabled by trade, and trade exists to create wealth. As a single concept, they are - cooperation with specialization? Value through cooperation? Mutually beneficial cooperation? ...ah. Commerce is the word she was looking for.
Then, what links commerce with laws? Well, commerce needs good and well-enforced laws to flourish, but so does approximately everything else. In the specific context of commerce, laws are necessary to build trust and reduce risk. But in the context of, say, civilization, laws are necessary to incentivize the right behaviors, solve tragedies of the commons and encode Schelling points. Those things don't reduce to commerce. So what's the more general concept that unifies commerce with all the other reasons to have laws?
Commerce is self-interested behavior that arises naturally; you don't need to pass laws to create it, only to enable it. Indeed, legally mandated exchange is not commerce in the free-market sense of the word. That's not to say legally mandated exchange should never happen; taxation and eminent domain laws both serve the public good. And what about money? It's a foundational concept which isn't obviously included in any item on the list, but neither is any kind of mathematics and it's not as if you can do without that, either.
If you conceive of laws as collective agreements chosen by the community, then they are a kind of trade. Yes, that feels like she's on the right track. The trade is the act of passing a law; the law itself is the artifact, like something you buy at market. In which case, the common idea behind commerce and laws is simply - deals. Mutually beneficial deals, freely entered, within some larger framework like a constitution or contract law or the free market. (Osirion isn't a republic and enslaves all its women - never mind, that's not even compatible with 'trade' and 'wealth', so let's conveniently ignore it for the duration of this thought-exercise being read by Abadar.)
Finally, what unites deals-under-a-framework with civilization? Civilization is something people want and will make deals to achieve. And it's a framework or collection of frameworks for living and making deals in. Possibly a specific one, magically knowing Osirian doesn't make her a walking encyclopaedic dictionary, but that's the most obvious quality of civilization - and it's also the end result of people living in that framework, making deals, passing laws, trading and growing their wealth. Civilization is what you get at the other end. Civilization is human sapient flourishing.
It's hard to give a name to the unifying concept, which is both a process and its result and so much of its structure. Some famous philosophers gave up and simply called it the Good. Tanya will call it -
Community rationality sanity wisdom enlightenment the Way cooperative flourishing.
Humans are a social species. It's only together that they amount to anything, and the more they cooperate the more they can build. Abadar must think so, as well.