Princess, brother-in-law love story series.

Answer 1

High-quality female novels that included princesses and brother-sister relationships included:
1."Royal Sister, I Was Wrong." Author: Spicy Persimmons
2:"After I wrote to my best friend, I became her sister-in-law." Author: Mu Youqian
3."After Rebirth, I Raised a Tyrant into a Group Pet." Author: When is dinner?
The following is an introduction to these novels:
Xie Shu sacrificed the first half of her life for the family. The family abandoned her, but she did not complain. She buried the palace for nearly five years and was forced to end up in a marriage alliance. Fate had given her another chance to choose. She loved freedom. In the past five years, she had treated it as her returning the favor of raising him. From now on, she only wanted to be a selfish person for herself. However, why did this child come to her side?
[Su Yan Version] For the first half of his life, he lived a carefree life. Later on, smoke rose everywhere, and mountains and rivers shattered. The ups and downs of his life were just to revive the old mountains and rivers. Su Yan said to Xie Shu,"Sister, you will always be with me, right?" Later, Su Yan saw that his sister was good to another man, and the knife in his hand moved up and down, just for her happiness.

2."After I Transformed Books with My Best Friend, I Became Her Sister-in-Law"
[Cold and aloof female general X delicate and carefree king]
Yan Yunqing X Biluochun Ye Mochu
[Weird Xi and Princess X, the cold-blooded Northguard General]
Ruthless Flower Destroyed at Night X High Mountain Flower Yan Yunheng
Country X's Shadow Force Captain, Yan Yunqing, died while on a mission. He accidentally transmigrated into the book written by his best friend and became Yuan Country's Zhenyuan General, Yan Yunqing.
What was even more unbelievable was that the author of this book, her best friend Ye Shiran, also transmigrated into the book and became the unfavored Princess Xi and Princess of Yuan Country.

piece by
The emperor has decreed a marriage.
Yan Yunqing was furious.
Ye Shiran (pitifully): I…I don't know either.
Looking at this delicate and scheming green tea man in front of her, Yan Yunqing suddenly had a headache.
Ye Shiran (trembling),[Why don't…you just make do with it?]
A murderous glare flashed.
Ye Mochu thought, Sister, why are you so fierce?
Yan Yunqing's mouth twitched.

Fragment 2
Night Shi Ran: Qingqing, save me!
Yan Yun Qing slaughtered everyone, who dared to touch her!
Ye Shiran felt really good hugging someone's thigh!
Wait a minute, is that the younger brother?
(Shout) Little brother is so handsome, so handsome, big sister wants to marry you!
Yan Yunheng was speechless.
One day, Yan Yunheng was drunk.
The corners of Ye Shiran's mouth curled up,"Good sister, well done!" Hehe, little brother, you're mine!

3."After Rebirth, the Tyrant Becomes a Group Pet": In her previous life, Su Jihua was the Princess of Beichen. When she was a child, she was a hostage in an enemy country. When she grew up, she was sent as a gift for marriage. Her husband's family was destroyed and the emperor went missing. After that, she diligently supervised the country for her father.
Even if she was forced to marry Luo Fusang, the monarch of the enemy country, she would not have any complaints.
When she realized that her father and brother were harmed by Luo Fusang, she could no longer hold it in and jumped down from the city tower.
After she was reborn, she vowed to protect her family, so the people in front of her wanted to get rid of Luo Fusang.
Finally! He still couldn't bring himself to do it…
Forget it, then I'll raise him into a little trash who only knows how to eat, drink, and play.
Who knew that this little fellow was becoming more and more clingy to him and even became the group pet of the entire Beichen Imperial Palace.
In the blink of an eye, eight years had passed, and her parents were still alive. Beichen was prosperous and the people were peaceful. Su Jihua was assigned to the handsome, tall, and powerful Crown Prince of Guyue Country.
Before getting married, Su Jihua suddenly felt a little reluctant to part with the little guy she had raised for eight years.
"Fusang, I won't be able to protect you in the future. You have to learn to protect yourself."
After that, Luo Fusang disappeared for three days.
Three days later, Luo Fusang returned to Beichen with blood all over his body. He held the national seal of Guyue Country and knelt on one knee in front of Su Jihua's palace."
"In the future, let Fusang protect my sister."

I hope you like these novels.