I never read anything about offering parts of Silesia, since the whole point of Maria Theresa fighting all those Silesian wars was to regain Silesia for Austria, though I do know that she and Augustus of Saxony (and separately, King of the PLC) had agreed to partition Prussia between themselves. Seeing as Russia was a crucial member of that last alliance, I doubt they would allow Poland to annex any part of Silesian, since Russia still needed to keep them weak, more or less. I also doubt Maria Theresa would want to give up any part of Silesia either.
Still, all history is ultimately speculative in hindsight since none of us were there, this is all based on deduction and inferred reasoning. There's not even any record of Polish troops fighting in any of these wars, which is why I highly doubt the Poles would have even gotten a tiny hamlet as a reward. Ultimately, Poland was always in the way of Prussian, Russian, and Austrian ambitions and none of them likely had any interest in throwing the Poles any kind of bone.