Leaning comfortably on the mic stand with her right hip stuck out and her left knee bent, comedian Laurie Kilmartin surveyed the Thursday night crowd at Zanies, sizing the audience up anew after each punchline and visibly recalibrating where to take things next: go darker, lighten it up or add in some fresh interaction and crowd work. In a long-sleeved black shirt and jeans, the veteran comic — who has been performing for almost three decades and writing for late-night television for almost two (currently for “Conan”) — clearly relished the ups and downs of playing with a full theater, testing the boundaries and the fine line between eliciting laughs, gasps and even the occasional silence. Eyes full of hope and a sly smile on her face, she delivered her unstintingly fatalistic brand of flippant comedy to a receptive crowd. Kilmartin — who opened by apologizing for looking like conservative provocateur Ann Coulter — is not one to shy away from the darker aspects of life (or death). Her most recent special (released last year on NBCUniversal streaming service Seeso) was aptly titled “45 Jokes About My Dead Dad” and, as the title suggests, focuses on the passing of her father, with an often irreverent tone. Along those lines, she has a book coming out in February called “Dead People Suck: A Guide for Survivors of the Newly Departed.” So death — her own, her loved ones’ and her not-so-loved ones’ — isn’t just not a taboo topic, it’s one of her primary focuses. “My 79-year-old mother moved in with me,” she said. “It’s temporary. Because she’s 79.” It’s not just the specter of our inevitable deaths that she delved into for comedic purposes during her 50-minute set. One of her other main themes is child-rearing, and how emotionally taxing it is. Kilmartin highlights her experiences as a single mom, and in 2012 she co-wrote a parenting guide with an unprintable title that made the New York Times best-seller list, filled with bracingly cynical tips for raising children (and chapter titles like “How to Not Hear the Baby in the Middle of the Night”). “I can’t believe my son is 10 years old,” she gushed Thursday night. “I remember when he was so tiny he fit on the front