Research has demonstrated the facilitative effect of morphological word families on the development of orthographic representations and children's spelling accuracy. Specifically, related words that pronounce silent-letter endings increase the accuracy of children's attempts at spelling these particularly challenging French words. The current study intended to replicate and extend these findings in large-scale analyses assessing spelling accuracy by word for a large corpus of French words spelled by 40 children in Grades 1 through 5. Results supported the word family hypothesis in demonstrating the facilitative effect of morphological word families for all children. The derivative diversity hypothesis extended research on adult orthographic representations in finding that the diversity of derivatives was the stronger predictor of spelling across grades. Finally, the feminine form hypothesis was generally supported in that the feminine inflection was related to spelling only in Grade 1, however, this was only after controlling for the diversity of derivatives.