Camilla, 77, and Anne have grown close since Her Majesty joined the royal family in 2005 following her wedding to King Charles.

Queen Camilla and Princess Anne took part in a rare joint engagement on Nov. 20, and when Queen Camilla attempted to break royal protocol and let her sister-in-law the Princess Royal walk in before her,

Britain's Queen Camilla has pulled out of an event on Friday night as she continues to experience some symptoms of illness after suffering a chest infection earlier this month, a Buckingham Palace spokesperson said.

Queen Camilla was presented with a special honor by none other than her sister-in-law, Princess Anne. Camilla, 77, was awarded an honorary doctorate of literature by The University of London on Wednesday0.

Princess Anne, who is widely known as the hardest working royal, appears to also be a stickler for the rules because, the royal just refused to break protocol even with Queen Camilla's permission. On Wednesday,

Britain's Queen Camilla pulled out of one of the royals' most high-profile annual events on Friday night as she continues to experience the effects of a chest infection that she suffered earlier this month,