Thanks for your query.
Hypopigmented spots on perianal region and now spreading needs to be examined.
I suggest you to get her examined by pediatrician
Worm infestation especially pinworm causes perianal itching,for which deworming with albendazole
needs to be done and is to be repeated after 15 days.
For cracked she will need a mild steroid
Hair around anal region is common,there is nothing to worry.
Wishing your child good health.