I have a JR (aged 3), we got her as a present for my then 5 year old. She now is my dog as she spends all day with me, either working with sheep, pigs or any other task.
She is an excellent worker in a sheep fank and takes no prisoners when working with the pigs. She likes to think she is boss and has the distinct impression that she is higher in the pecking order than even my husband, but she gets reminders of her position in our house.
I trust her with kids and she knows to get out of any situation that might not work in her favour.
I'm a firm believer that dogs are what you make them. They are born with certain traits but most of their behaviour is the way they are treated.
You get out what you put in!!!