I think parents shouldn't underestimate how much their kid absorbs at a festival, big or small! I got taken to Glastonbury at nine-years-old with a friend and for me it was the most surreal but memorable weekend of my life.
As a small person, every colourful character, smell, taste and sound was somewhat magical.
My friend and I liked to make up stories about the people we saw walking past - such a thieves, delinquents, rock stars etc - kids really have developed senses of humour by that age!. Oddly I am grateful of even the toilet memories too, plus tons of life experience to never forget - like developing a great par with the surrounding adults.
Is this your business?