There are a couple of freeware apps listed here that claim to be able to edit existing PDF files. However, if Photoshop stymied your client, these probably will as well.
http://forums.whirlpool.net.au/index...e_PDF_Creators
You might just want to quote her a price for editing the text in the future ($10 a pop sounds about right to me, not bad for a couple of minutes work, and fair to her as well).