Bottom line the D3200 sounds decent as a video rig and very good as a stills sensor.
We were just discussing Shutter Priority when shooting video, and using exposure compensation to control Aperture, and it worked on my D7000. Would need somebody to try it on a D3200, but my guess is it will not work (based on reading between the lines in the D3200 manual, but I could be wrong). The fact the D3200 allows "Manual Movie Settings" may be more important than controlling Aperture. And the fact that the D3200 allows for an incoming stereo microphone is an advanced feature.
Also consider a J1/J2/V1/V2 for video and stills for your wife. The on sensor PDAF is a feature unrivalled on any DSLR and could be particularly handy for video.
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