Frances Margaret Irby, Lady Crofton's, article in thepeerage is here. She married three times.
From pinterest.com/theideallife/aristocracy; clines caused by cracks in the glass negative fixed with Photoshop.
This image can be found on a wedding dress site. Lady Margaret is lovely and so is her wonderfully lavish debutante dress in this Lafayette photo. This photo shows her dress has a sweetheart neckline.
Keywords: 1906, Lafayette, Frances Margaret Irby, Lady Crofton, Irby family, Crofton family, British, bouffant coiffure, feathered headdress, tiara, veil, sweetheart neckline, elbow length close bare shoulder sleeve, pouter pigeon bodice, close skirt, train, lace, necklace, earrings, debutante dress