Kentucky Attorney General Daniel Cameron is not married to Mitch McConnell's granddaughter.
Mitch McConnell has three daughters with his first wife. They are named Porter, Claire, and Elanor. Mitch McConnell does not have any children with his second wife. Makenzie Evans' mother's name does not match the last name of any of the three daughters of McConnel.
Further, the communications director for Cameron’s office Elizabeth Kuhn had denied these rumors and mentioned it as untrue.
Apart from rumors being spread on Social Media, there is no concrete evidence to show that Makenzie Evans has any blood relation with Mitch McConnell. Thus, the claim of Makenzie being McConnell's granddaughter is not true.