If you are the only two members of an LLC, and you live in a community property state, then you report the business on two schedule Cs, one in each of your names, each reporting half the income and expenses.
However, if you do not live in a community property state, or the LLC has more members than just the two spouses, the LLC MUST file a separate business tax return form 1065. For this, you need Turbotax Business, which is a separate program from the personal version of Turbotax. As part of filing the business tax return, you will prepare a K-1 statement for each partner that lists their share of income and expenses. The K-1 is included on each partner's personal tax return. The deadline for form 1065 is March 15, not April 15, unless you get an extension, and the penalty for late filing is $195 per month per member.
As to whether it is better to file your personal returns separately or jointly, that can only be known by testing both ways. But it is almost always better to file jointly.
