I see no issues here either to be on the safe side.It costs little more to form a trust, and there would be NO legal problems ever for wifey to hold/possess/use any NFA item in the trust.
As the NFA approval is about a year now, just cancel the application (ATF will refund the 200 bucks) form a trust with HeavyD, and resubmit for the SBR stamp.
I was only addressing the issue of using what was readily available to defend ones self.
Best thing would to have “something else” readily available. LOL