My biggest concern with this piece is that her eyes are equally rendered, which made them equally competitive and the viewer may get lost between the twos. Would be nice if the further eye on the lft is slightly weaker (especially the high light) than the closer eye on the right. Also would be nice if her nose tip can be a little lighter so people don't get last in that big gap between the eyes. The value of the letter is too close to her skin tone, it is not obvious enough and not sharp enough (since it's paper it should not be fuzzy). Make the letter sharper and add some more red into the heart on the letter would make the letter jump out more, since it's about valentine's day, it would be good to emphasis the theme. Her mane on the right side has sharp edge, which makes it looks like a paper cut out. Make it softer and weaker would be nice. Otherwise it's very well rendered, great job!