Not necessary.  A few of my colleagues told me that their backgrounds  in China were checked.  But you do not have to worry about it, normally the company will send the candidate's info to an agency in China if they want to check the candidate's background in China.  It is the staff at the agency that make the phone calls and verify some of the info.  Since those are Chinese, they will not have problem to under your wife's situation.  Just in case that result of background checking is negative, you sure can explain this to the company.  This is US.  You can argue about pretty much everything.   Good luck.