Stars in her Eyes by Betty Cavanna (1958)

Magda Page's family and friends had reduced her distinctive first name to just plain Maggie, but no one could tarnish the luster of her last name. Maggie, in her early teens, was a little too plump and not very sure of herself; but Maggie's father was the famous television personality whose show, "Peter Page Presents," was known from coast to coast. Maggie longed to look glamorous (though not enough to make her curb her appetite), to be attractive to boys (though she didn't quite know how to go about it), and, above all, to appear triumphantly on her father's television show.  (from the inside flap)