Ranavolana, I mentioned British English not out of any favouritism, but because that is an area where your phrasing towards Granny has a particularly strong meaning that is quite possibly not what you thought. If you're going to use phrases which mean something different to them than to you, don't be surprised if they get angry. You see, in British English, that last sentence has already happened...
Anyway, I get your other points too, I think. My main point was not to take sides, but quite a few posts ago now to highlight a difference in language use, specifically because English is so varied around the world.
JJ, reading as neutrally as possible, Granny has been criticised multiple times for simply offering to do her best for somebody asking a question, which you have also now acknowledged, so thumbs up from me. Your issue is 'related' - I get that - however, I don't think Granny meant that 'you' couldn't resist, but Ran, which she pretty much confirms later.
Anyway, grievancies have now been aired, as they say. GL to you both.