Translation:The girl wants to ask 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.
Why is it "κάνει" rather than "ρωτήσει"? Would it be wrong to use "ρωτήσει"? I remember reading in another discussion the differences between languages. Like in English we "ask" a question, while in another language you "leave" a question. In Greek do you "make" a question?