Ahoy! The Lass' been 'round longer than I recalled!
Found an old sketch from Autumn of 2004, hidden away in an untouched-since-college box of sketchbooks.
Turns out I'd doodled up a character that is essentially Bonnie about a year earlier than I thought! I imagine this was just a nameless piratess and her bird at the time, sketched out just to come up with something new, but she's clearly a precursor to what would eventually become the Bonnie we know and love today!