That sounds most unfair, and I am sorry that you and your siblings had to endure it.
As for Sarah Ferguson - I have never seen such out of control attention seeking. Even when we were 10 year olds, I think we were more mature than she is.
It was the 50s and 60s. Kids were taught to behave. Parents didn’t need ritalin. My mother could slap my up side the head and scream “Pay attention!”