By Emma Mackenzie In the Royal Family, hierarchy is everything. It’s the foundation block on which the system of monarchy is built, and those inside the House of Windsor take it really seriously, which is why the royals are so often seen curtsying and bowing to one another, depending on their position in the system itself. That’s why there are two royals that Kate will always have to curtsy to, despite the fact that her husband William is first in line to the throne – the highest in the line of succession – and she will one day be crowned as Queen alongside him. An etiquette expert – Myka Meie…