Well, faces are generally skin and some fat over a variety of muscles covering the front of the cranium, the cartilage of the nose and the jaw. It also contains the eyes, eyebrows, and eyelashes. One might also consider the ears a part of the face - these, like the nose, are simply skin over cartilage and a small amount of soft tissue.
The face is generally used to communicate by expressing emotion. Additionally, various parts of the face allow the person to see, taste, hear, balance, and smell.
I believe that all of these things are applicable to the face of the subject you have provided. She also appears to have added makeup, which is usually various types of minerals as well as color additives, and to be using her face's communication abilities to express her happiness and excitement.
Do you need any more explanation of what her face is?