How can I convince my mom to quite smoking?

She is 51 and she smokes. I want her to be around when I have my kids. I want her to quite she already tried but she couldn't. How can I get her to quite. I don't want to hurt her feeling but at the same time I don't want to hurt her. She wants to quite for me and her 5 her old granddaughter. Also I heard anyone over 50 should have a colonoscopy. Would it also be a good idea for her to get one of them too.