Totally agree. I feel as if she didn't merely act, but became the character just like all her other roles, but in this role she had more screen time and even though Xiaoyu was supposed to be one-dimentional (just sweet, innocent), she went beyond that and touched the depths of my heart.
I just cried thinking about how much she loves Chengxiang and is willing to sacrifice for him and not letting others hurt him.
I think I'm going to rewatch this series again, just for the journey of it. This is certainly one of the best things in my life.