It seems that Belgian RF and Spanish RF have thorough plans for preparing their respective heirs to become head of state.
Elisabeth started at university then the military training.
Leonor is starting with military training then university.
Christian and Amalia don't seem to have plans in place - and it shows.
By 17-18 years old, both Elisabeth and Leonor already had small, age-appropriate royal engagements without their parents and where they were the focus.
I haven't seen that yet with Xn and Amalia. Amalia follows her parents around at their engagements, but seems mostly lost at those events.
Not sure I've seen Xn even following his parents around at their royal engagements. If it's happened, it hasn't happened often.