Lifestyle – Appearance->Header not showing

Hi, I’m using the Lifestyle child theme, and a client just notified me to find out why his header has disappeared. I checked his site, and sure enough, the header is gone, and there is no longer the option to go to Appearance–>Header. “Header” is no longer in the dropdown menu.

Can you please help?

http://wordpress.org/extend/plugins/genesis-simple-headers/