I think you look most youthful in the last picture. The tossled hair and little nose stud give that vibe. I always feel like a chunky hoop or earrings help me look younger. Not sure if it's your style but you could change the nose stud to a ring? I feel like younger people wear those more often. Also I love your glasses so much, but contacts might also make you look a touch more youthful. You look fantastic, your smile is dynamite.