COGS for Previous Inventory

If each piece of art has a unique item number, simply set up a second set of inventory, sales and cost of goods sold accounts. Ex:

•  Inventory Asset - Her
• Sales - Her
• Cogs - Her

Then edit each of the items in the item list to reflect the proper accounts.  Eventually, all of the separate property assets will be sold and the accounts can be inactivated.  However, since she bought most of the inventory before marriage, it's probably less data entry intensive  to edit the joint items rather than separate property items.  Also, the account changes can be made by exporting the item list to an IIF file, making the changes using excel and reimporting the IIF file.  If your not comfortable with import/export, I'd suggest finding an advanced proadvisor in your neighbor hood to help.