My ignorance on this matter is exceeded only by my ignorance of the thought processes of the fair sex, so I'll limit my two cents to questions.
Did CSS "Ponchartrain" receive EXCESSIVE attention from Adm. Porter?
Orders of battle might answer this, if they're available. In 1863, what boats did the Confederates have on the Western Rivers, that could dispute (or potentially dispute) Union control of the Mississippi River? Did Porter pay equal attention to these others, measured by the distribution of his own forces?
Who initiated the message exchanges in ORN regarding "Ponchartrain," Selfridge or Porter? If the former, then the subordinate's natural focus on local affairs seems a reasonable cause, with or without the stimulus of first-in-his-class ambition. If the latter, then did the admiral also initiate messages regarding the other Confederate craft?