Your translation attempt has several grammar errors, but even after fixing them, your sentence is only going to mean something along the lines of "Is she telling the story commonly known as _Like Brass_?" ("commonly known as ", "what people call ") is not something you need here. is "to tell a (long) story", which is not a right verb, either.
If you want to repeat someone else's statement in a mocking or surprised manner, all you need is //:
* Is grammatical?
* Variations on sentence-ending !? (used when repeating something in surprise)
* ~ why is there a here?
> (polite at least superficially)
>
> (informal)
>
> She is "like brass", you say?
(By the way, I have never seen such a simile as . Is this common in other languages? Or is this "brass" supposed to mean something other than that yellow metal?)