Hi there, @Slfike.

You can reconcile the parent account as the transaction from sub-accounts flow to the parent, once you reconcile the parent account it automatically reconciles the sub-account.

Here's how to reconcile:

Make sure to have your bank statement, review the opening balance and match the balance of your real-life bank account for whatever day you choose to start tracking the account in QuickBooks.

1. Go to the Gear icon, under Tools column select Reconcile.

2. On the account drop down in the middle, choose the account to reconcile.

3. The last statement ending date should be your bank statement starts the day after your last reconciliation.

4. Make sure the beginning balance in QuickBooks matches the one on your bank statement. 

5. Enter the Ending balance and Ending date as they're written on your bank statement.

6. Once done click on Start reconciling.

Let me add this article on how you can compare your bank statement and QuickBooks and review or change reconciliations: Reconcile an account in QuickBooks Online.

You may also want to know on how to adjust a reconciliation, feel free to read this article: How to adjust a reconciliation.

You can drop any question here in Community, I'm always here to answer.