Raelle didn't have as many thoughts as her siblings. She had clearly accepted them a long time ago. She was willing to listen to them and get along with them. It was just those two who hadn't found the rhythm of getting along with her yet. But they couldn't be blamed for that either as they hadn't known her for even a year yet.
Shui Xian was able to figure her out soon after their marriage because Raelle didn't intend to keep anything from him. She wanted a transparent relationship and that's why they didn't have to stumble along to understand each other. Besides, Shui Xian was her husband and with her sense of responsibility being so strong, Raelle would try her best to share everything with him.