Greta Gerwig is to star in "How I Met Your Dad," a spinoff of the popular U.S. sitcom "How I Met Your Mother," CBS announced. Gerwig will play Sally, a free spirit on the verge of breaking up with her husband after less than a year of marriage, Variety reported. The actress will co-write and produce the show, the entertainment industry trade newspaper said. Gerwig's film credits include "Frances Ha," "To Rome with Love," "No Strings Attached" and "Greenberg." From: UPI