First Impression: When giving a critique I normally spend up to 30 minutes in the process, constantly viewing the image and must say this will be a pleasure as Christin is simply beautiful.
Composition: I've tried using my cards to see if I can create a better composition but think you have it pretty well spot on here.
Subject: I'm a 50 year old guy so won't comment ;)
Technical: One of your commenters felt the dof was a little off but I dissagree and think the only bit that might have looked better with a slightly deeper dof is her fringe but thats just nitpicking.
Final thoughts: The eye contact between subject and viewer is great, I gave this a 7 during voting, it would have been at least an 8 if we either saw more or none of her right earing and the background was different as it doesn't add anything to the image and is a little distracting even oof.
I feel that with a title like "simple beauty," one should be using a model who is less made up and dressed simply. I also think the DOF is just a bit short.