I thought it would be "An bhfuil rud nua é?"
It's the difference between the copula and the verb bí. When something is a classification sentence, you use the copula, not bí.
So the declarative version of this would be "Is rud nua é"?
Yes. Is rud nua é means "It is a new thing"
She runs the "e" into the word nua so it sound like it's one word.
Is this also the way one would say "Is it something new?" in Irish?