"When does she work?"
Cultural sidenote: あなた, かのじょ and かれ are often omitted, use someone's name or あの人(あのひと) instead!
- あなた sounds rude to keep using it more than needed; I think it's kind of like pointing at the person every time you say it, which is a tad off putting.
- かのじょ and かれ usually mean "girlfriend" and "boyfriend" respectively, using them to simply mean she/he is also a tad off putting; I think people would usually assume you'd ask when their girlfriend works when you say this!
- It's very common in Japanese to use someone's name while you're talking in their face, so feel free to do it! (not in English though, people will be like "Why are you asking what games Fonzie likes? I'm Fonzie!")
- あの=that over there / 人(ひと)=person. "When does that person work?" / "When does she work?" when you don't know her name, again this is normal in Japanese. (again not in English, "that person" sounds a tad rude to use out of the blue, in my experience)
they are very similar in usage, but 働く is a word that implies labour while 仕事 is more akin to "job" in English. There is also another one 勤める【つとめる】"to be employed" which is used for jobs that are profession related, or jobs where you will be employed for long periods of time.
Am I mistaken, or should the かのじょ not be required? Omitting the subject in Japanese does not mean that the subject is "me", as Duolingo seems to have suggested in this and past lessons; it just means that the subject is irrelevant or must be inferred from context. In English, this is grammatically unacceptable, so if the subject is too obvious or unimportant to say out loud, a pronoun is used instead. While obviously it all depends on context, the English sentence "When does she work?" implies that the context is a conversation about some feminine third person. That means that if the speaker just says いつはたらきますか, the listener can probably tell that they are speaking of "her". Otherwise, the English equivalent "she" would probably also be too vague. It is possible that the context is one in which "she" is specific enough, but no subject at all is not, for example if the conversation is about a feminine third person, but talk has recently shifted to the listener. Then かのじょ would be needed to specify that the subject is not あなた. However, it seems to me that this is an uncommon situation, and anyway, Duolingo should accept answers that to conform to all reasonable contexts.
That would also be an acceptable translation.
There is a slight difference technically. しごとをします is basically "do your job," meaning your profession that you do to make a living, while はたらきます is just a generic term for "work." So for example if you were talking about doing work around your house on the weekend, you could use はたらきます but not しごとをします.
Since the question doesn't really specify what kind of work you're talking about, you should probably be able to use both.