The question is very strange. Can not imagine myself asking this question from a person but anyway I am grateful for every new word I learn :D
Interesting to note: In Hungarian we even use "nyávog" as another word for "whining". So in this case it could not only mean a cat impersonator but someone who is whining. "Ne nyávogj már!" = Stop whining! You're welcome ;)
But you could ask your cat. I often speak to my cat in Hungarian - he never judges my poor accent :-)
Does the verb come from the sound of the animal or does it come from somewhere else?
I'm guessing it comes from the sound. I can imagine a cat's meow being described as "nya."
I think that you would hear "you are meowing?" only in certain ethnic neighborhoods in New York City