Traveling Through the Book to the End of the World: Cannon Fodder Becomes the Protagonist

Find a Novel with an Organization That Has a Female Protagonist with a Mafia Background. Called Seven-Leaf Flower

An organization with a female protagonist from a mafia background. It's called Qiyehua and the male protagonist has two children named Huanhuanyanyan, the male protagonist is Yechen, the female protagonist is a designer of guns, and the male protagonist is more carefree. The book begins with the female protagonist joining the male protagonist's company.