Long Lost Princess

Megan Cerenes has a normal life. An older brother who is overly concerned with his looks, an awesome mom and dad. The only part that's abnormal is the lack of memories from before she was 8. However, there's a secret, one that has been whispered through the country. Of a secret so big, the crown is at stake.
How does she tie in? Megan Cerenes is actually Princess Ellia of Lidane- the lost princess.