In This Life, I Won't Live as My Twin Sister's Shadow

Only on the verge of death did I realize I'd been deceived my entire life by my perfect twin sister. Shocked by the betrayal, I wished I could just close my eyes... but when I opened my eyes, I was back in my childhood!? I had to pretend to be a princess with my sister without letting her know I was a twin! Now that I'm back, I won't just live like in my past life, being taken advantage of by my sister. The relationship with my family I'd longed for, the friendships I had with my friends, the healing power I hadn't realized in my past life. I'll make then all mine! Then, by chance, I met the talking bird, Yan. He told me that if I didn't protect him, the kingdon would fall. What did he mean? Will I be able to survive?