Dear affy25,
I would encourage you to have your sister take her daughter to an eyeMD.
Whitening of the pupil is concerning and needs to be examined by a professional. The
whitening occurs due to appearance of the tumor on the retina causing a change in the normal red reflex. Other diagnoses which can cause this reflex change include cataracts, glaucoma, retinal abnormalities such as colobomas, and high prescriptions [refractive errors].
Dr. Feldman
Sandy T. Feldman, M.D., M.S.