Why aren't there little Shenyang and Liu Yong in Princess Huanzhu?

Although Princess Zhu Huan is fictional, she still respects history. In real history, Yongqi is nine years older than Xiao Shenyang. Even if Yongqi faked her death at the end of the third film, Yongqi is 25 years old and Xiao Shenyang 16 years old. At best, she is a child. In the early days of pearl return, little Shenyang was still a little doll. The prosperity of small Shenyang occurred at least 20 years after the return of Pearl, so. There will never be a small Shenyang in Princess Zhu Huan.