Translation:The girl wants to ask a question.
Following what I learned from other dicussions about subjunctive, shouldn't this sentence better be "το κορίτσι θέλει να έκανε μία ερώτηση"? Since it seems more likely that she is wanting to ask a (single) question (once), not continually be asking a question?
When we say aorist form, we mean the aorist form of subjunctive. So, το κορίτσι θέλει να ψάχνει=the girl wants to search (continually) w'ont become το κορίτσι θέλει να έψαξε but να ψάξει=the girl wants to search (once). It's like taking the present form and "replacing" the few letters before the word's ending. Κάνω has the same present form as the aorist form. The aorist has one more form "κάμω" which is not used tht much.
It depends on context. What if girl is "making a question by adding word Why to the sentece" - I mean she is learning how to make questions in English? Im not saying that its more often, but its clearly possible.
Duolingo is about learning the basics and everyday uses of a language and should not require the teachers/tutors/creators to accept every possible oddball translation, otherwise we would all learn nothing.