Dear kisue,
I would recommend that you take your daughter immediately to see an a pediatric eyeMD to determine the cause of the white spot. A number of different conditions can cause a white spot to be centered in the pupil and I would recommend that she get checked to determine the diagnosis.
Dr. Feldman
Sandy T. Feldman, M.D., M.S.
ClearView Eye and Laser Medical Center
San Diego, California
By "dark area", do you mean the pupil (the black, round area in the center of the iris (the colored part of the eye))? If so, you are probably describing an anterior polar cataract, or small density (or tuft) in the capsule of the lens in the eye behind the iris. It may be associated with an additional whitening (opacity) of the underlying lens. These are not usually visually significant, and do not usually go away or get worse, but it should be checked out, as larger ones can cause problems with visual development, and it could actually be something else instead. I recommend a pediatric ophthalmologist. You can find one online at the AAPOS (American Association of Pediatric Ophthalmology and Strabismus) website.