by Davo Smith.
Really this is a request that belongs in the Contrib plugins forum ( https://moodle.org/mod/forum/view.php?id=44 ) as it is related to a specific 3rd-party plugin, rather than a general Moodle development question.
However, as you have asked, the asnwer is no, not without some custom development work.
The text added via mod_etherpad is stored on the Etherpad server, not in the Moodle database. You could look through the Etherpad API at: http://etherpad.org/doc/v1.2.6/ and see if you can spot any way to retrieve the text entered by a specific user, but, from a brief glance, it appears to only support retrieving the whole of the text (for a specific revision), not that for a particular user.