I received a cleverly spoofed email reply asking for tax information: How do I diagnose and solve the issue?

I believe my email or device was hacked: how can I verify and how can I resolve it?

Here is what happened:  

My wife sent  an email to my accountant which contained a few minor bits of information and I got a response that read (with bad grammar):

"please email me your Drivers license and 1040 from last year. I did a system update and lost many informations. thank you"

and below that was included a copy of the email text I sent to my accountant.

First, it is obvious that this is a spoof due to the bad grammar

But, my questions are

(1) How could a hacker manage to send me a faux reply that contained my exact original message?
(2) This email was sent from an IPAD, does that suggest my wife's email is compromised. the IPAD is compromised or both?

Thanks,