Genevieve,
No need to worry. The Project Management Institute (PMI)® requires you to send proof for three items on your application. You simply have to follow the instructions.
They need:
• Verifying Bachelor's/equivalent university degree.
For this you need to send them a photocopy of your degree paper.
• Verifying your Project Management Experience.
In your application you have included a number of projects, with descriptions of your work and the total number of hours worked. PMI wants your "manager, supervisor, or colleague who is intimately familiar with the experience on your application" to verify that what you have submitted is correct.
As it so happens, a colleague of mine is being audited right now for his PMI-ACP application, and because I am his supervisor, I have to do exactly this. He included 3 projects in his application, so yesterday he sent me 3 PDF documents titled "Agile Experience Audit Reports" that PMI has provided to him. I printed these documents, signed them, and then I had to put these documents into a sealed & signed envelope. I am planning of going down to FedEx later today and ship them to him overnight.
You and your supervisor will have to do exactly the same. You download the documents from PMI, and then he/she will have to do what I did. PMI even provides instructions that you can give him/her.
• Verifying 35 contact hours of Project Management Education.
You are a customer of The PM PrepCast and you probably already completed the Final Exam and received your certificate of completion. Simply print a copy of that certificate and include it as part of the package you are sending to PMI. (If you have not yet received this certificate then please open up the PrepCast Student Handbook L00.10. You can find an explanation on how to take the final exam somewhere in the first 15 pages of that document. Check the table of contents.)