no. petite is short AND small build not necessarily super thin you can still be petite and be alittle heavy or any type of body shape (pear/apple/hourglass) it's just a nice way of saying "short" but most people apply it to tiny girls in general
I would say she has a "petite build", but petite is usually defined as 5'4" or less with a small/thin build. At 5'8", you're taller than the majority of girls, so I wouldn't call you petite, no.
My term for what you are is "greyhound", because like a greyhound, you are long (tall) and thin. Female vollyball players are often greyhounds, and some female basketball players, though they tend to be a bit thicker.