Can you recommend a finished time-travel novel with a female protagonist?

When the female protagonist's boyfriend and sister (I remember that they were half-brothers) got married in the church, the female protagonist, who should not have known, came because of the task assigned by her mentor. She mysteriously disappeared in the church and returned to the church during the reign of Emperor Kangxi of the Qing Dynasty (the priest of the church was also an old man who had passed away). Later, Kang Xi gave her the identity of the daughter of a Bannerman official and used her to observe and select his sons. In the end, she got together with a second brother (not a fourth brother). Also, the female protagonist's sister and boyfriend had also transmigrated before her. The female protagonist's sister had an ambiguous relationship with the future Yongzheng Emperor, and she even disguised herself as a man to act as his strategist. The Fujin was also wearing it. They followed the path of fantasy. In order not to change history, those who had to die or would definitely die, and those who the female protagonist cared about, would use something that looked like a soul calling pearl to retain their souls after death. Finally, they would travel back to the modern world together (Emperor Kangxi also went to the modern world, but although his body was young, he felt that his mind was already old, so he returned to the Qing Dynasty in the end). It should be said that he still remembered the plot very clearly, but he couldn't remember the name. I hope someone who knows can tell me, thank you ~ Err, please note that it's a clear transmigration, and the reason for transmigration has been written clearly. Those who don't know, please don't write the names of a few more famous transmigration novels.