My wife started a small business, LLC, solely in her name. We used to file Married-Joint. How should we now-?
You can still file jointly if you wish. In a single member LLC, your wife can report the business on a schedule C of your joint return in the same manner as if you did not have a LLC. The IRS regards a single member LLC as a disregarded entity.
The schedule C is included on your personal 1040.