She wasn't working for the Stasi, she studied physics and has a Ph.D.
However she excelled at Russian and mathematics from a young age, that must be especially grating to Vladimir Putin — I suspect that her Russian is better than his German. ;) 
Did she apply her excellence in mathematics to real estate? Not as far as is known.
In short Angela Merkel is no dummy. LOL  
And from what I've read, she doesn't suffer fools gladly, either. ;)