I hadn't watched that before.
It's behaviour that would look tacky at a very unroyal wedding, for example, let alone a public church service for the Commonwealth.
Presumably, seating arrangements for such an event would normally be such that people would file into and out of rows of seats in a set order.
The fact that, apparently, things had to be rearranged because of H & M's grumpiness and self-importance, may have led to the seating order not being as polished as usual.
But surely she should have waited and followed those in the seats in her row, not shoved through like it was the first day of the sales?
Lucky they weren't in pews: she'd have found it tricky clambering over the back of one in that dress.
To give her credit, though - I'm sure she'd have made a spirited attempt.