The Secret Language of Sisters by Luanne Rice

Ruth Ann and Tilly are sisters and best friends. Ruth Ann is in a car accident which leads to her suffering with locked-in syndrome and Tilly is the only one who can see past the still silence. Tilly is also fighting the guilt of growing feelings for Ruth Ann’s boyfriend. The book is told through alternating perspectives to see if Ruth Ann will wake up and if Tilly will be able to forgive herself.