As the account holder I have added my wife. She does not have all the access to account management and other options that I do. This should be an option for those who would like it.
Example, I can go into my child's transaction history and on a specific transaction I have a button to "pay back" my child for the purchase. My wife does not have that access to that button.
Additionally, it would be great if the child has the ability to send a "bill" to either parent for a purchase. Especially when the child is using his/her greenlight card to run errands or purchase items for the parent or family