Image Credit: Valerie Macon/Getty ImagesVictoria Tennant (L.A. Story) has joined the cast of Lifetime’s William and Kate, the TV movie about the romance between Prince William and Kate Middleton. Tennant will play Celia, the woman who gives middle-class Kate etiquette lessons. Nico Evers-Swindell (NCIS: Los Angeles, Law & Order) portrays the heir to the British throne, and Camilla Luddington (CSI) is the future princess. William and Kate also stars Ben Cross (Chariots of Fire) as Prince Charles. The movie begins shooting this month and is slated to air in April.