Iron Blooded - Seventeen: Without Mercy

Ye Qing transmigrated into a novel. She was only an unimportant character in the novel, and she was free to live a wonderful life by herself.

But, her happiness was short-lived. One day, an adorable girl that looked around three-year-old popped up and called out in a milky voice, “Mom.”

Ye Qing: ???

On another day, a cute and handsome twenty-something guy hugged her. With tears in his eyes, he said in a voice that was full of affection, “Mom!”

Ye Qing: ???

After Ye Qing had somehow inexplicably become the mother of two children, she discovered –

Neither of these children were human!

***

One day, a little girl pulled a certain big boss to the side to whisper, “Dad, mom was patting my head when she was telling me a bedtime story. I felt too comfortable, and I accidently swung my tail out. Mom seems to have seen my tail. What should I do? QAQ.”

- Description from Novelupdates

The daughter of Prime Minister is a nympho?
The brutish Prince is her husband?
The stroppy Princess wants to kick her husband off the marriage sedan?!
“Shit! I want a divorce!”
“Why?!”
“You can’t satisfy me in bed!”
The next day, Prince Chen becomes the laughingstock of the whole Kingdom of Dayue.
How Hua Yueling, the Stroppy Princess with a soul from 21st century, will create her legendary story in this ancient world?

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

“Do you like me?” “Yes...” “When did it start?” “A long time ago...” “Will you always like me?” “The fireworks...will always be with you...”Looking at her upturned face, the girl's timid hand was gently lifted up. The warmth in her palm has always been so familiar. “Want to go watch the fireworks together?” “Yes.”The summer fireworks blooming in the deep night are just like your touching and tender smile twelve years ago.----------------------------------PS: Youth daily life story, childhood friend single female protagonist.