it sounds like the problem is on your customer's end. I assume she's using Adobe reader. In any case she should open a PDFs NOT sent by you and see if it prints.
Before you Saved a record as PDF, you need to check some tasks.
1. Depending upon your printer option the page size may vary. So If you installed one or more printers in your system, there issue starts. So for last what setting you used for last Print (It may be word file, excel file etc..) that setting only will apply for your PDF in FMP12.
3. Do rough copy once, then verify yourself. After attach the file and send it to Customer.
4. If PDF reader problem (Acrobat), try this step > PDF Issue
I checked the options, it is for 7 or higher.
Yesterday I sent her a PDF I got off of the internet, it printed.
Check the printer itself, and its driver. I have sometimes encountered a problem similar to this (nothing to do with FM) with PDFs downloaded from email or internet sites which refuse to print on my oldish laser printer but print happily on my cheap inkjet.