[There is an unexpectedly touching ending to The Sky Is Free,] a story that reflects the flinty, harsh life of the opal mining country. Characterization, dialogue, and setting are of equally high quality. (p. 73)
Zena Sutherland, in Bulletin of the Center for Children's Books (© 1977 by the University of Chicago; all rights reserved), January, 1977.
[The Hundred Islands] takes place on an island off Australia where Greg, Jenny, and Darryl have grown up together and where Greg, dead serious about the island's ecology, now confronts his hard-working sheep farmer father, who thinks feeding people is more important than saving wildlife. Greg is willing to help Dad on the farm if it's run his way (no poison, a vermin-proof fence), but when Dad sticks to his terms Greg leaves home…. The problem though is not that Greg, like many his age, thinks in self-righteous black and white, but that Clark's presentation of the issues and actors is just as heavyhanded. (p. 672)
Kirkus Reviews (copyright © 1977 The Kirkus Service, Inc.), July 1, 1977.
Set among the hundred islands in the Bass Strait off Tasmania, this story is centred on two teenagers, Greg and Jenny, and their deeply-felt concern for the islands' wildlife. The Hundred Islands is a sensitive and poignant novel, with an important message about conservation and the future. Mavis Thorpe Clark creates a vivid atmosphere and a sense of isolation and beauty in her descriptions of the islands and the birds and animals. The relationship between Greg and Jenny is developed carefully and convincingly, although it never dominates the story completely it is the means by which we are given hope for the future. (p. 232)
The Junior Bookshelf, August, 1977.