Defiance by either one would require time out in their room for 6 or 13 minutes, respectively, or instant bed time depending on the severity of the offense. Persistent defiance would invite a well-planted spanking on the seat of the pants for the younger one. The older one would be grounded for a week or more, depending on the offense. We have expectations of our children. If these expectations are not met, they lose privileges.
Defiance is a much more serious offense.
Most offenses can be attributed to forgetfulness, wilful or otherwise. However, authority must be preserved if defiance is exhibited.