Actress Kristen Bell has revealed that her and Dax Shepard’s 5-year-old daughter, Delta, is still wearing diapers.   She made this revelation in the latest episode of her digital series Momsplaining, which falls under the umbrella of the Ellen DeGeneres show,   Speaking to Bridesmaids actor Maya Rudolph and Happy Endings actor Casey Wilson, the 39-year-old talked about the different experiences in potty training each of her children.   She said: “My oldest daughter at 21 months, we merely suggested that she …