Tuan:
They are freckles. She can treat them with a lightening cream containing
hydroquinoneHydroquinone
Hydroquinone and sunscreen
Hydroquinone topical 2%. If that doesn't work over a period of 2-3 months, she can see a dermatologist for stronger creams, or perhaps chemical peels. And don't forget sunblock!
Best.
Dr. Rockoff