Mary Poppins (Allison Fernberg) and Bert (J.T. Schaeffer) in “Mary Poppins: The Broadway Musical,” which opens at 7:30 p.m. tonight and 2 and 7:30 p.m. Saturday. The musical runs Thursdays, Fridays and Saturdays though July 21. There are 2 p.m. Saturday matinees each weekend.