Hello there, @DnR75040.

I'm here to help provide some details about setting up Owners Equity sub-account in QuickBooks Desktop.

When you create a company, there are specific accounts that QuickBooks creates by default and other special accounts that you can't delete, merge, or set up a sub-account. These accounts are:

• Undeposited Funds
• Opening Balance Equity
• Retained Earnings
• Inventory/Stock Assets and Cost of Goods Sold/Cost of Sales
• Reconcile/Reconciliation Discrepancies
• Unapplied Cash Payment Income
• (Sales tax agency name, such as GST/VAT) Payable

What you can do is create another separate Owners Equity account, and from there you can set up a sub-accounts. 

For additional reference, you may want to check this article to understand QuickBooks Chart of Accounts. 

Please know that you're always welcome to post if you have additional questions about setting up an account. I'll be around to help. Have a good one.