Does she have any associated symptoms of itching etc?What is her age? Is there any history of trauma or injury to the site?
There are several causes of white spots on the skin. You would have to consult a skin specialist to find out the definite diagnosis and rule out tinea versicolor, pityriasis alba, vitiligo, lichen sclerosis et atrophicus and secondary to healing process after an injury.
Pityrospum ovale or Tinea Versicolor is a yeast like organism - treatment is with oral medication called Nizoral , topical are not that effective.
Another possibility is a form of eczema called Pityriasis Alba- treated with topical cortisone.
She could take some oral antihistamine or antiallergic medications like loratadine or cetrizine and see if it helps with her symptoms. Apply calamine lotion at the site of the lesions to help soothe the itching.
Let us know about what the skin specialist advises and post us about how she is doing and if you have any other doubts.
if she's outside alot and tanning, it could be sunspots also. it's just a fungus that grows that doesnt allow that spot to tan. you can easily get sunspot treatment at either your doctor or you can even go to a tanning salon and ask for sunspot treatment... but im not a doctor, but it could be that...