If an eight year old girl is playing in a FIDE rated event, she should know the rules – regardless of her age. Otherwise, let her play in US Chess rated events.

If it is a FIDE rated tournament, the FIDE Laws of Chess apply – without exception. …
Yup. And I am still not going to penalize an eight-year-old girl with the loss of a game because she forgot to press her clock, and five minutes later when she realizes it, presses it with the wrong hand.
FIDE, like U.S.Chess, has a rule 1A. It’s called the “FIDE Preface”. Situations like the one described above cry aloud for it to be used.
Bill Smythe

If an eight year old girl is playing in a FIDE rated event, she should know the rules – regardless of her age. Otherwise, let her play in US Chess rated events.
We do explain the rules quite thoroughly before the event. Still, the States nominate the girls. Whatever their criteria, it is possible for a young girl to her state’s nominee. Typically, the youngest nominee is 8, sometimes 7. They are invariably at the bottom of the table, and lose anyway. I will not embarrass them and take away their enjoyment of the game because they pressed the clock with the wrong hand or castled with two hands.

Same with that silly capturing the King thing in blitz. Do that in a FIDE tournament, and you lose.
It’s not that simple.