The search for a "Portraiture plugin for Photoshop 7.0 free download" is often fraught with technical hurdles. Software compatibility is rarely backward-compatible indefinitely. Modern versions of Portraiture (version 3 and 4) are designed to work with 64-bit operating systems and recent Photoshop versions (CC 2015 and later). Photoshop 7.0, however, is a 32-bit application designed for Windows 98, ME, 2000, and XP.
. Official versions are available for purchase or as a trial through Imagenomic Finding a Version for Photoshop 7.0