Rockabilly Baby (1957)

The mysterious Mrs. Eleanor Carter moves to Springfield with her two teenagers, Jimmy and Cathy. Eleanor makes friends with the town's social leader, Mrs. Wellington, who supports her idea for a town youth center, and she is aided by Tom Griffith, the high-school principal. At the town's annual picnic, to which Eleanor has bought a band (Les Brown and His Band of Reknown), the town busybody, Eunice, reveals what she learned about Eleanor's past.