Possible Clues:

• -- Downs, Racetrack and Casino, venue in Louisiana
• Poem by Longfellow about the exiles of Acadia
• Longfellow's poem this girl won't conceal
• She had a Norman cap and ancient French ear-rings
• 'Even I may be concealing an angel within' suggests Longfellow poem
• Eponymous girl in verse from tall chap, and from curtailed poet
• In poetry, when she passed, 'it seemed like the ceasing of exquisite music'
• 'Forest primeval' figure