FRIENDS INDEED: Lena Dunham isn’t the only screenster who is in tight with Zac Posen. Gia Coppola and Gina Gershon, who have both been chums with the designer for years, caught his Monday night show. Getting into the family business, Coppola is a director like her grandfather Francis Ford Coppola and her aunt Sofia. Her first flick, “Palo Alto,” is based on the book of short stories by James Franco. Due out in May, the tales of promisicuous high schoolers will feature Franco, Emma Roberts and Val and Jack Kilmer.