"Does your daughter like candy?"
Translation:האם ילדתכן אוהבת ממתקים?
The word "daughter" can be translated either as בת or ילדה, both are not 100% equal to daughter, but they are the closest
This is an interesting point actually.
Both of the following:
- ילד / ילדה
- בן / בת
readily lend themselves to being altered, in order to specifically express the meaning of 'son' or 'daughter' (rather than just 'boy' or 'girl) to the forms
- ילדכם / ילדתכם
- בנכם / בתכם
respectively, with the meaning more or less.
In English, in any case, "your boy" or "your girl" feels quite different somehow, compared to the very common (and formal) "your son" or "your daughter".
Why should "your" in ילדתכן have to be plural? I put ילדתך (which may not be quite right either).
It doesn't have to be plural at all. It's just a problem within this course. Remember that it is still in beta version. Just report that your answer is correct, as I did ;)
Your translation is perfectly fine. Also, looking the the sentence Duo offers as the translation, it may be deduced from it that the girl's parents are both female, a detail that is not revealed in the English sentence.