Translation:Her name is Rania and she has a small dog.
I think this absolute correspondence between "large" and "small," and "big" and "little" is just a construct of ESL books. Real language is more fluid than what is taught to foreigners sometimes. And you can, as a matter of fact, say "large dog" in the right context. It just sounds a bit euphemistic. That said, you should report it if "little" isn't already accepted.