What is the proper usage of the phrase “due diligence”?
There is another question that has been asked similar to mine but I didn't find any of the answers had completely answered my question. I have a friend who said, "I think we have used enough due diligence to prepare for this test," and it didn't quite seem right.
After some brief research on the proper definition of "diligence" and the meaning of the term/phrase "due diligence", I'm still convinced that she is incorrect in her usage. I am curious as to what the community has to say about her response to me. Keep in mind that she's a very arrogant individual who was trying to appear more intelligent than she very well may be.
If this is the incorrect usage then what, specifically, is faulty about her sentence structure? I'm trying to build up an arsenal here so that I am 100% correct once I correct her.