BALLET TO BE REPEATED BY REQUEST: One of last year's prettiest numbers in "Juniors on Parade," the "Crinoline Days" ballet, is to be introduced again in the second act this year, in response to many requests. Three of the dancers are shown above. They are, from left to right, Jean Reynolds of Montclair Pl., Nancy Cory of White St. and Betty Lou Cox of E. Huron St. The dance revue will be given from Wednesday night through Saturday next week in the Lydia Mendelssohn theater, for the benefit of St. Joseph's Mercy hospital children's department.