It is said that Yongzheng was a relatively pure-hearted emperor among all the emperors of the Qing Dynasty, and he was not particularly eager for male and female love, and the number of his concubines was very small compared to his son Qianlong and father Kangxi, so his children were not many.
Taking Yongzheng's sons as an example, after Yongzheng's death, only Hongzhi was able to compete with Qianlong for the throne, and the other princes were either too young or had already dissolved the father-son relationship with Yongzheng. And Hongzhi this person is particularly absurd, so Yongzheng has no choice, Qianlong can become emperor is not how good or capable he is, but forced.

From this aspect, we can also see the thinness of Yongzheng's heirs, and the son is good to say, after all, the throne only needs one person, but feudal society prevails in marriage, especially the Qing Dynasty is the world on horseback, the original population is not dominant, so the Manchu Rulers have always attached special importance to marriage with Mongolian nobles.
Compared with his sons, Yongzheng had fewer daughters, only one of whom grew up healthy, and only lived to the age of 23 before he died. After Yongzheng succeeded to the throne, there was an urgent need to solve the problem of peace and affinity. After thinking about it, Yongzheng came up with the method of adopting a daughter, and the first daughter of Yongzheng's brother Prince Zhuang, Yunlu, entered the palace under such an opportunity.
According to the "Draft History of the Qing Dynasty", the daughter adopted by Yongzheng was named Rourou, and historically became Princess Heshuo Duanrou. It is said that Princess Duanrou, as the concubine of Prince Zhuang, has lived a life of pampering and pampering since birth. She is not only excellent in appearance, but also a girl with excellent intelligence, and her poetry is all familiar.
The lively and intelligent Princess Duanrou immediately received a different favor from Yongzheng after yongzheng ascended the throne. In the first year of Yongzheng, Princess Duanrou officially entered the palace as Yongzheng's daughter, because she loved to be spoiled, so Princess Duanrou developed a more stubborn nature after entering the palace. But no matter how much Yongzheng pampered her, he did not forget the real purpose of adopting her as an adopted daughter.
In the eighth year of Yongzheng, out of political needs, Yongzheng arranged for Princess Duanrou to marry Borjigit Zimmerzi, the king of Horqin County. Where is Mongolia, which lacks nothing but the moonlight, compared to the capital city that wants everything? As soon as Princess Duanrou heard about this, she showed a resistant attitude, and even kept crying and crying for Yongzheng to take back her life.
This time, Yongzheng did not compromise with her as usual, but gave Princess Duanrou two choices: either to kiss or to die. It was such a sentence that made Princess Duanrou see Yongzheng's cruel and ruthless side as the emperor of the Qing Dynasty, and she knew that Yongzheng could do what he said, so she did not dare to be willful anymore.
But Princess Duanrou did not compromise unconditionally, she was indeed a very intelligent woman. Before getting married, she made a request to the Yongzheng Emperor, hoping that Yongzheng would give her more domestic slaves and allow her to occupy more territory in Mongolia.
As long as she is willing to be kind, Yongzheng is of course willing to agree to her. Moreover, Yongzheng also hoped that Princess Duanrou would be happy in his heart. In this way, in the eighth year of Yongzheng, Princess Duanrou took her domestic slaves to Mongolia and married Borjigit Zimmert Dolji.
These house slaves did a lot of great things for the princess after she got married, and after Princess Duanrou occupied the land, she selected some capable people from these house slaves to carry out the planting industry for her and manage the industry for her. Because of their existence, Princess Duanrou's glory and wealth can be enjoyed inexhaustible.
It is worth mentioning that the land of Gongzhuling was originally a lord and belonged to the domain of the Second Prince of the Mongol King, and since this person had no queen, this land was inherited by his brother.
However, Princess Duanrou didn't care about this, after seeing this land, she directly called someone to camp here, and the brother of the second prince of Wang was no longer dissatisfied and did not dare to offend the princess, and could only eat this dumb loss. From this incident, it can also be seen that Princess Duanrou's personality is really not a rumor.
Resources:
"Princess Table of Qing History Manuscripts", "Records of Emperor Shizong of the Qing Dynasty"