LOS ANGELES â When Rob Marshall, the director of the film âMary Poppins Returns,â realized that Dick Van Dyke was the same age as the grizzled London banker he played in his second role in the original 1964 âMary Poppins,â Marshall had a eureka! moment: Why not ask Van Dyke, now 93, to play Mr. Dawes Jr., the bankerâs son, for the sequel? At the time, Marshall had not met the tripping-over-the-ottoman star of âThe Dick Van Dyke Show,â but the filmmaker wasnât worried that Van Dyke wasnât up t...