Great composition, exposure and technically developments and yes i love the most is expression with beautiful eyes. Really very expressive portrait in park.
Very nice. My grandson now 21 has those eyes and I too was fortunate to have photographed him in color at about the same age as your subject. Not a critique but have you considered cropping the image just above the sleeve line of her left arm? I think it will draw one's eye more to the face and present a stronger image.