[Grace Themes]

Hi Erika,

To change the height of logo image
Go to Appearance -> Theme Options-> Basic Settings -> Logo -> Change your custom logo height

If you want to change the width of logo section (bigger horizontally)
Go to Appearance -> Editor -> style.css file
and add below css code at the end of file

.logo { width:30% !important; }
.header_right { width:70% !important; }

Regards
Grace Themes