How many cannons went off when YOU were born?
Protocol dictates that Her Majesty the Queen finds out about royal births before anyone else - even the newborn's grandparents. Apparently when Prince George was born, Prince William called Elizabeth II on an encrypted phone to tell her the good news.
But don't worry, they didn't forget about Kate's family. Per Vanity Fair, "Then there were calls to Kate’s parents in Bucklebury, her sister and brother, Prince Charles and Camilla, and Prince Harry, all of whom were relieved and elated in equal measure."