I do not recognize the logotype at the bottom left of the card, but believe it is for the Lafayette studio.
Queen Mary's hair is wavy - not curly. This photo also shows the details of her sleeves. She wears a small brooch - just two pieces.
Keywords: Queen Mary, Princess, Queen, Teck family, Windsor family, British, straight coiffure, tiara, square neckline, over-dress, quarter length length notched tight over-sleeves, under-dress, quarter length tight under-sleeves, natural waistline, close skirt, choker necklace, necklace, earrings, brooch, bracelets, fan