For example, recently, I said something along the lines of "Nan, I'm just popping to Stratford today, I need a Benefit counter in Boots"
DNan: WHY ARE YOU GOING TO A BENEFIT? WHAT BENEFIT? 
I reassured her it's just a name for a cosmetics brand. She was still left very 
Me recently: "Nan, I'll need to leave the house at about 2 because my train leaves at 3"
Nan: Are you sure? Let me get Antonio to check (her son, my uncle)
Me: Nan, it's fine. I have stuff on my phone that tells me about delays and train times in seconds. It's all okay
DNan: "OKAY, WELL YOU KNOW BEST. NO TELLING YOU. MISS YOUR TRAIN. SEE IF I CARE 
"
DNan: "You need to feed that baby some meat. Not that vegetarian shit. That boy needs protein! That's why he's so small"
I reply that my nephews are veggie (DS is Vegan for allergy reasons) and absolute beastly boys on the 100th+ centile. She doesn't seem to register.
How do I deal with these responses? 
I look back and shrug, but at the time it's draining!