Who the hell does my grandmother think she is? The boss of the world?

My mom is downtown for something, and she's not coming home for dinner because she has a physical therapy appointment, and it would be out of the way for her to come back here and then go to p.t.
My grandfather just called and said that he can't get home because the trains aren't running. My grandmother said that she should've asked my mom. I said that my mom's not coming home, and she said "She'd drop him off."

UGH!! SHE IS NOT THE BOSS OF MY MOM!

My grandmother just called me downstairs to ask if I'd drive into town. Ok...one year ago she was in a car accident. And I'm justified in being afraid of driving, especially to downtown on dangerous roads. I told her that, and she got mad at me. She has no right to get mad at me for being afraid. I am fuming now.
I suggested that he take a cab home, and she said "I'm not paying a lot of money for him to take a cab when we have a kid here." She meant a kid to drive. I'm not their personal cheauffer service. And I'm scared, ok? Why the hell wouldn't she understand that? And I know for a fact that my mom wouldn't let me, anyway. My mom wants me to drive downtown with her in the car the first time I do it.
My grandmother said she takes back ways, but I don't trust her judgement. She's been really weird recently.

I beter stop. I am just so pissed off.