I'm going to say my girlfriends grandma should just do the world a favor and die
Why would you want your girlfriends grandma to die?
Her grandma is always shouting and grumbling at any given moment, it's annoying.
You should not think such toxic thoughts about anyone, even if they are annoying. If you can try to get along with your girlfriends grandma, it would save all of you a lot of stress and drama.
She's just a pain in the ass, people like her should just take a flying leap.
Wanting someone to die because you don't get a long with them is a pretty extreme emotion and not something you should openly admit too. Try to talk to her grandma and see if you have something in common, even if it is your strong willed natures!