Meghan Markle’s heartwarming nickname for Prince Harry was heard during the couple’s latest appearance. The Duke and Duchess of Sussex visited the family of a teacher who was killed in a school shooting in Texas. Irma Garcia was killed protecting her students during a mass shooting at Robb Elementary in Uvalde in 2022. Footage shows Meghan and Harry at the family’s home singing Happy Birthday to the mother of Irma’s nephew, John. Before singing, the duchess turned to her husband, Prince Harry and called him: “My love.” The heartwarming exchange took place as the duchess held a birthday cake an…