"My stepdaughter is my husband's daughter."
Translation:Ma belle-fille est la fille de mon mari.
I constructed the sentence ... 'Ma belle-fille est la fille de mon mari' which was accepted ... however I believe that 'belle-fille' is the translation for 'daughter in law' ... and 'Demi-fille' (the correct translation for stepdaughter) is not available for selection into the sentence
"Demi-fille" is not a French word. This is why it was not available for selection.
Please use a dictionary if you are not sure about a word.
"Ma belle-fille" is the same for "my daugher-in-law" or "my stepdaughter".
"Demi-" is used only as "demi-frère" (half-brother) and "demi-soeur" (half-sister).