Prince William and Kate Middleton already have three children; Seven-year-old Prince George, 5-year-old Princess Charlotte, and two-year-old Prince Louis. Could the Royal couple be expecting their fourth child? Is Kate Middleton pregnant for baby number four? Since neither Prince William or Kate Middleton will not let anyone know for sure one way or the other, we have to take a guess on our own by watching for different signs and body language on Prince William instead of Kate Middleton. Prince William is the one who gives off signs with his body language. Kate Middleton does not show any signs or give off any signs in body language, except that she usually has terrible morning sickness with her pregnancies.