ESL Discussion

Hello ;

I was study English and I saw the sentence below and I want to know why the "not" become before "mention" instead become after "did" .

The sentence is ;

Which item did the girl NOT mention about her needed supplies for school?

But I think it is a negative question form and as I learned it must write down like this ;

Which item did  not the girl mention about her needed supplies for school?

Can you someone clear it for me ?

Thanks a lot