Karen -- Apple doesn't want you to be able to use the Camera Connection Kit to transfer files.
From the Apple page iPad: Using the iPad Camera Connection Kit:
Only device-created files are supported. If you copy files from another device or manually edit or rename files on the digital camera or SD card, the iPad may be unable to detect and import these images or videos.
I would ask on the iPad discussion forum (that the files are being exported from Aperture makes no difference: you want to know how to transfer files to your daughter's iPad from your computer using (presumably) the Camera Connection Kit, or, barring that, something more direct than iTunes).
I currently use the iTunes work-around, though I am likely to switch to a Dropbox file folder sync or something similar. The iPad/computer/camera/iCloud/iTunes/Aperture/iPhoto nexus seems be entering its teen-age years: an exciting growth spurt, accompanied by confusion and some unexpected behavior.