"The Queen isn’t a fan of wedged shoes," a source once told Vanity Fair.
"She really doesn’t like them and it’s well known among the women in the family."
However, sister-in-law Kate Middleton is a big fan of wedges and often wears them to events she knows she'll be walking on grass.
But, the Duchess of Cambridge is careful not to wear them at events the Queen is also attending.
So, seeing as Her Majesty isn't in Sydney with the royal couple, and considering they were visiting the beach, maybe the Queen might let this one slide.