Don't have HEM, but in PT3 the stats that show are playername dependent.
So for example, if I had never set my alias's to show me all of DJ13 (stars name), I would never see any stats from FullTilt where I am dj1113. As it is, I have set my alias's, and sometimes update to include other players alias's as I find them out.
So assuming you and your wife have different usernames, (you better have or this HEM issue is miniscule compared to other impending issues), you should only be seeing your stats or can adjust it to only see your stats.
The data mining issues is different, as most sites will be restricted to some # of hands before you will stop importing fresh hands. In PT3 I believe it is 25-30 hands. This number is controlled by the poker sites
as interpreted by PT3, and I assume HEM. Failure to abide will cause the trackers to be placed on the 'FORBIDDEN SOFTWARE' list.
I could also see how a non-me player has done against another non-me player in situations where I was at the table. So I could see how Joe Showdown has done against Savage Penguin over the 2 years (or is it 3?) that I have collected hands.