Hello Abachelorgirl,

There is also always a possibility to export your Invoices from the old company and then import them in batch by the use of different third-party apps. If you manage to get your invoices stored within .xlsx(excel) , csv or .iif file and you need them to get  appeared in any desktop version of QuicKBooks that is not older than of 2012  you can get an app, I was using a lot, named Business Importer for Desktop.

That is rather intuitive tool that will help your processes  to get done in a fast and convenient manner. Moreover, they have an indeed friendly support team that can help you to expedite solving your tasks should you have difficulties using the app.