Hey Maria, this is really nice, your digital painting skills are really good. The thing that jumps out to me is your drawing. Its clear from the way you drew the head that it's turned slightly to the right (our right). Yet, the nose and mouth are drawn straight ahead. This makes them look off the center line and makes the drawing look "off". I did a quick sketch to show you what I mean, I hope it helps :)

Great construction of the facial bones and features, @Maria J Venegas-Spadafora! Pretty good lighting too!