My daughter is 14 and just got rid of pinworms shes got very skinny and always hungry because of them so how can she now get fat or gain more/alot .?

Pinworms? : Pinworms usually are not symptomatic or cause rectal itching. They don't affect appetite, food absorption or other upper GI functions. Do you mean tape worm, hook worm or ascaris?

See her pediatrician: If she eats, drinks & pees a lot & doesn't gain weight, your pediatrician will search for a medical cause, like diabetes or other systemic illness. Pinworms wouldn't cause these symptoms.

Pinworms: Don't cause you to be skinny. They cause your anus to itch. She can gain weight by eating healthy high calorie food containing fats from avocado, olive oil, fatty fish, etc.