I would say, in the form of chastisement, yes it would be external force. Unless its a “hey son will you do better” without coercion of threat or punishment if they dont than it cannot be said to be of ones own “free” will as there is an external factor influencing his decision against his will to not have that external factor applied. Not that it is necessarily bad, but it is force none-the-less. If a choice is made because external factors or pressure is influencing the decision then it is hardly "free"will or unrestrained which is in the definition of the idea of free will.
If the child says “i do not want to be reprimanded”, and is still chastised, then by the very act of chastisement against there will is an act against there “free” will.
Not to blow it out of proportion but none would hardly say a man with a gun to his head is making a choice of his own free will. Mainly because an external force is being applied to influence his decision.
Thus is adams sin and Gods judgement. External forces that influence our being, apart from our will to be a part of it or not.
The very idea of judgement and chastisement, having no say in wether we want to be a part of it at all or not, is the very definition of external influence and force. And so it cannot be said that it is not forced upon the unwilling (take for instance an atheist).
I posted these verses on the faith/works debate topic but figured Id share here to lend scriptural credibility to my argument for any who may not be over there as well.
"But who are you, a human being, to talk back to God? "Shall what is formed say to the one who formed it, ‘Why did you make me like this?’“Does not the potter have the right to make from the same lump of clay one vessel for special occasions and another for common use?…”
“for to vanity was the creation MADE SUBJECT – NOT OF ITS OWN WILL, but BECAUSE of HIM who DID SUBJECT it – in hope,”
“for GOD did shut up together the whole to unbelief, that to the whole He might do kindness.”
“‘HE hath blinded their eyes, and hardened their heart, that they might not see with the eyes, and understand with the heart, and turn back, and I might heal them;’”
“For it is by grace you have been saved, through faith—and this is NOT FROM YOURSELVES, it is the gift of God—not by works, so that no one can boast.”
Those are definitely limits set by God, and obviously limits mans will so that it cannot be said to be “free” to go against what He has subjected man to.
Also side note, i have two accounts now. one for my phone