Is this sentence used in every day life?
Yes, I heard people say it about you ;-)
Now, no kidding, yes when it is deserved, we can say that, but there are other less pompous expressions, like: "elle est très/extrêmement intelligente", "elle est brillante".
"She is highly intelligent" , normal English, not accepted.
It translates the general idea, but perhaps not close enough to the words.
She has a high degree of intelligence, Wrong?
It is not wrong, but it won't help you remember un niveau = level.
Is the pronunciation correct? I only heard "ella ah ah" niveau d'intelligence. Had to reach for the slow pronunciation to get it. This one's very tricky.