Lena Dunham , Allison Williams, and Jemima Kirke are 3 daughters of a good mathematician "Geroge".

When I asked George the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters ?

Lena Dunham : 2 , Allison Williams : 5 and Jemima Kirke : 7

Age diff : 7-2 is 5 , 7-5 is 2 and 5-2 is 3 which all are prime numbers