I am nervous about inviting my girlfriend over?

I am currently in high school i gonna graduate this year, my girlfriend is a junior. I wont be seeing her as much after i graduate because i am gonna be going to college. Me and my girlfriend have been dating for about 5 months. My parents want to meet my girlfriend so do my grandparents. I invited my girlfriend to dinner with them. I am worried because my grandparents are racist. My girlfriend is black,native american, and white. I am just pasty white, blue eyes, and blonde hair. what should i do ?