The name Mackenna is a girl's name of Irish origin meaning "son of the handsome one". Mackenna and discussed in our forums with posts like "Sibset makeover game! B/G pairs".
From the experts:
Although the Mc or Mac prefix always means "son of", the first names McKenna and MacKenna are used in the US exclusively for girls, with the McKenna spelling outpacing this one 14 to 1. There are no boys recorded with either spelling of the name.