I feel like this is one of the hearts of the problem: that many of us were taught to always be polite about a gift, and this Nanna is exploiting that.

And like...I still want people to be polite about stuff beyond the giver's control. If a young person has their heart set on a $$$ item and their family can only afford a $ knockoff/equivalent, that's a great time for a young person to learn to smile cheerfully and say thank you. If someone genuinely tried hard and did not know about a particular factor--a new allergy, say.

But there has to be a line, and this Nanna has long since crossed it. Asking a question like that is not actually attempting to know her grandchild, it's attempting to force her grandchild to behave in her desired way. Not okay.