Her article in thepeerage is here.
From eBay; sepia tone removed.
Baroness Louth wears robes over a dress with bodice cut in half by a seam at Empire height, but that also appears to be narower at natural waist height.
Keywords: 1911, Eugénie Bellairs, Eugénie de Miaritze Plunkett, Baroness Louth, Bellairs family, Plunkett family, Baroness, British, bouffant coiffure, coronet, veil, robes, quarter length close sleeves, square neckline, upper bodice, Empire waistline, elbow length sleeves, cuffs, natural waistline, close skirt, brooch, court dress