Her bouquet must contain this one flower
This is another tradition started by Queen Victoria married Prince Albert. She had sprigs of myrtle—known as the herb of love—in her bouquet. After the wedding, Victoria planted a myrtle shrub in her garden at the Osborne House on the Isle of Wight. Every British royal bride since has carried a bouquet containing a sprig from that very shrub. Kate carried a small, rounded bouquet—designed by Shane Connolly— with myrtle, lily-of-the-valley, hyacinth and Sweet William. Most all of the royal bridal bouquets are white.