AITAH for refusing to eat a meal with my grandmother??

For context, I’m 20 years old with my own money. We were in the middle of the airport with a 3 hour layover and on our way to the gate my grandmother stopped walking and asked if I wanted anything to eat, kind of hinting she wanted to eat. I told her I’m good but if she wants to go ahead and eat that’s all good! I personally had some chips beforehand, if anything I was just thirsty. She side eyed me and said “you don’t wanna get something to eat??” And I said “..me personally..no”. She asked again a couple minutes later and I already said no. She got really visibly upset and angry and hasn’t talked to me much since. She’s a full grown adult and can buy whatever she feels like eating but we went back to the gate and sat down. I don’t really like when people choose food for me or watch me order when I can just go up and order food whenever I feel like it, I was stressed and didn’t want to eat in that moment. I’m fully capable of getting my own food and feeding myself which is what I basically did throughout the entire trip. I basically paid for myself. I also kind of pushed away her offers to get me food while on the trip because again I don’t like when people pick out food for me when I can buy and make the decision myself. But she ALWAYS does this when I don’t wanna eat a meal in full. I’m healthy and I eat well generally. Did I do something wrong?? Can someone give me a parent’s perspective?