First thing to learn:
In this case, you're not exactly legally married yet, so not being joint still makes sense.
But once married, what's yours is mine and vice versa.
With a joint account, the risk is that one party could empty the account and run off in to the sunset and frolic in the wind.
With individual accounts, the risk is that the other party may not be able to access the money easily.
I'm making some presumptions here:
Then pick any one of these:
What's SO to do about getting money? Obviously not enough in her account. Sure there are ways to work around these issues, but a joint account would give SO easy legal authority to transact.
But bottom line is, there's no absolute wrong answer. Every couple does their finances differently. Separate accounts in perpetuity can work for some folks.