Simone I. Smith is married to LL Cool J.Amy Sussman/WireImage for SIS InternationalSimone I. Smith shares four children and four grandkids with the rapper.She started a jewelry business to foster her passion for design.She learned about entrepreneurship and marriage from her grandparents, she says.This as-told-to essay is based on a conversation with Simone I. Smith, founder of Simone I. Smith Jewelry. It has been edited for length and clarity.E…