I am looking to delete my kids' accounts since they dont want to play any longer. How do I go about doing that?

You can not delete accounts, all you can do is stop logging into them. Free accounts will delete after three real life months of inactivity and premium accounts or any account that has been premium will delete after one real life year of inactivity.

You can't delete an account. As Idle Lane Farms said, it deletes after a certain point of time of inactivity.

Edit: Grammer