First day of year 11- brand new students

Two girls named Terra and Phoenix flair had a big secret that only they knew, they were independent and didn't need any adult supervision. They owned their own flat, went to school and went to lessons on time, made sure they paid their rents and so on. But the thing was they were orphans and element benders, but their life is about to become a huge maze starting on their first day of year 11.

First book: The grass and fire bender
Second book: The grass and air bender
Third book: The devil angel and the two broken hearts Fourth book: Rise of the Phoenix