I have a general policy of not divulging exact personal details of friends or family on the Internet without their express consent. But suffice it to say she was old enough to understand what the Stasi did, and lucky enough to have not been directly affected by them as an individual, although some people around her were: interrogations, permanent disappearances, etc.
However, not everything was beatings, disappearances and terror. Believe it or not, East Germany wasn't all downsides. People were employed, general crime was apparently quite low, children felt relatively safe, children were given education (though indoctrination was certainly a heavy component), they were clothed and fed. While the standard of living sounded like it was relatively low across the board, it also seemed that this standard of living was more evenly distributed than might have been the case in some other places at the time. Obviously traditional Communism has borne out to be more or less unsustainable, and I won't be participating in any debate about Communism vs other dogmas, but I feel I would not be accurately conveying all that I've been told were I not to mention these counterpoints to the Stasi's behaviour.
One fascinating thing my partner has told me is that for some reason, the memories she has of East Germany before the wall came down tend to be in black and white, in her mind's eye.
As you retell, the Stasi were quite big on the human intelligence angle, but I doubt they would have had to resort to such measures would they have had access to the kind of communication infrastucture that is common in the developed world today. Such a system as the NSA et al have access to now, would have been a Stasi wet dream, I'd imagine.