What if employees talk back to their faces or even speak louder than me?

My employees are older than me in small 8, and they contradict me! First of all, I give her a chance, because she also has her emotions and grievances. We are the bosses. Only under certain circumstances, leave the environment and treat her as your classmate and friend. Will we forgive him? Then criticize and tell him that there is no benefit. I hope he will support your work! Secondly, you should talk less about things in the company in the future. Being good to them is mainly reflected in work, not information!