Watch out for Talia Reinhardt

Who is Talia Reinhardt? Why does Headmaster Dumbledore go to great lengths to check up on her? Does Dumbledore simply favour this first year. Or is there something about Talia that makes her different from the rest. Could Talia be dangerous, or just a misunderstood orphan. Talia helps Harry Potter with his quest to keep the Philosopher's stone safe but can she really be trusted?