MC is only 12 going 13 while ML is 23. Which is something normal in the medieval era.
If you ever think the emperor is gonna change his status from a polygamous person to a monogamous person who is only loyal to MC.... No WRONG! That ain't happening. The emperor still sleeps with other females even at the end of the chapter. He only highly favours MC cuz he thinks MC is interesting and feels that if MC ever dies, the harem would be a boring place. He thinks she stupidly loves him but NOPE. MC is just good in acting that she loves and care for the emperor until the end. In the end, the emperor might have love her but it wasn't declared much. Like you can only see through his action that he cares for MC.
Overall, the story has a lot of mysteries of death, attempted murder on MC but failed in the end. The way the story potrays really is accurate base on the ancient china custom. No Cinderella fairytale story. Personally I feel this story is not as good as to be a virtuous wife.
the MC ended up the film emperor and not her childhood friend. I was misled due to the title of the novel.