Along the lines of the soggiest of Cookson's Mary Ann sagas in gushy implausibility--but with none of Cookson's earthy pizazz--this is the story of Hillary Rudd, daughter of the coxswain of the crack lifeboat team in a Norfolk fishing village. Called ""Little Fish"" by her loving Dad and tough Gran, and ""Copper"" by Robert Penn, an austere bachelor recluse, Hillary swims into world-wide fame at 14 by rescuing two dogs from an angry sea. (Says Robert Penn, owner of one of the rescued: ""I knew the first day I saw you that you were chartered for fame. . . . Now your name will go up in lights."") And on the strength of this mighty deed, Copper is offered a scholarship to a fine boarding school, with further studies to be financed by an anonymous ""guardian""--with whom she holds an affectionate correspondence over the years. But then there's an auto accident, killing Copper's beau (Copper herself, wiry though she is, barely squeaks through)--followed by a disastrous romance and marriage with a con man. All ends happy, though: a few busy concluding pages dispose of con-man Donald (over a cliff) and unite Copper with a man of true mettle. . . who is really her guardian. . . of course. Like most of Dwyer-Joyce's chirrupy efforts: sheer pish-posh.