Re: 6-year old manners
I don't know what the experts say. Maybe there are some good books out there. But I will tell you my personal story.
I remember clearly being six years old, being on vacation in Hawaii and doing something at breakfast time (the way I was eating) to send my mother into a fit. She spent the next two hours sitting with me in the restaurant teaching me all the rules of etiquette from eating to how to address people, etc. I know it sounds a bit crazy. And for those two hours I was MISERABLE. BUT...I remembered all of it and then became very proud of myself that I did have such good manners. How many 6 year olds know the rules of buttering bread, sipping soup and addressing their elders? I don't know if her methods were the best. But I will say that a six year old is very capable of learning, retaining and using their manners.
"Go slowly, breathe and smile" Thich Nhat Hanh