After an 18-year run with Saturday Night Live — where she co-created such famous recurring skits as Debbie Downer and the Spartan Cheerleaders, while only briefly appearing on camera — Paula Pell was approaching 50 when she began her second act.The celebrated comedy scribe, a frequent collaborator of Tina Fey and Amy Poehler whose credits include 30 Rock, Sisters and several Golden Globes telecasts, Pell is set to receive the WGA East's Herb Sargent Award for Comedy Excellence on Feb. 1.