Hi, Kelly. I appreciate the additional details of your situation. Let me join this conversation and help you further.

You can request to be invited as a Primary Admin to the three companies you'll take over. Then, use the QuickBooks Online (QBO) Advanced backup feature to copy each company file to a corresponding blank company file. Rest assured that this process will not require the use of a USB stick to transfer the data. I'd be glad to show you the process of accomplishing this.

First, as SIAB suggested, transfer the Primary Admin access to the three companies to your Intuit account. Refer to this article for the detailed steps: Request to be the primary admin or contact.

Since you have created three new QBO Advanced accounts, you can set up the Online Backup & Restore app for the six existing company files. Here's how:

1. Follow the steps to Turn on the Online Backup & Restore app for your QuickBooks Online Advanced data for Companies A and B.
2. Next, follow the steps to Turn off automatic backup for Company B only.
3. Then, turn off all automation settings in both Company A and B:
   1. Go to the Gear icon, then Account and settings.
   2. Select Advanced, then Automation.
   3. In the Automation section, turn off each option, then select Save.

For the rest of the steps to copy an existing company file to a new company file, refer to Step 3 of this article: Make a copy of your QuickBooks Online Advanced company.

For future reference, I'm adding this article for managing your Intuit Account if you need to update any account information: Manage your Intuit Account online.

We'll be here in the Community if you have further questions about importing data to QBO or requesting to be the primary admin of multiple companies. We'll do our best to assist. Take care!