MTL - The Rise of Space Technology - Chapter 89 , unsolved genetic technology

Gu Qingli, a modern-day doctor and poisoner, was killed by her best friend. She was reborn as a weak peasant girl who could easily be bullied. Not long after she returned home, her wedding was called off. Everyone in the village started speaking poorly about her. A greedy matchmaker showed up and tried to convince Qingli to marry an older man! The matchmaker had barely been gone for a few seconds before returning once again. It seemed that Xiao Laosan, a man from the same village who was famous for bringing bad luck to his partner, wanted Qingli as his wife. The matchmaker wondered why a wretched woman like her was so popular. Gu Qingli did not mind. She thought that she, a wretched woman, was a perfect match for this man. For the days to come, she'd take her younger brother with her to forage for herbs, and they'd stir up trouble when they got bored. Wretched woman? A failed investment? Those things had nothing to do with her!

This is an alternate history. Decades after the fall of the Eastern Jin Dynasty, the world is still in chaos, although there is hope for reunification.

After a vacation, when she returned to her country she caught her fiancé cheating. She angrily left and disappeared.

Five years later she returned with her talented kid. Afterwards, her son participated in the piano competition. Unexpectedly her son actually came looking for his father.

“The camera on this side, take me to take a look! My name is Xiaoxi my mommy is called Tang Siyu and she’s very pretty! I’m four and a half years old this year. I’m looking for my father, you probably look like me, please be sure to contact me, oh!”

After that, he was gone from the front of the camera again and said, “Oh, I’ll wait for you!”

In the background, a woman became mad. A few days later, a mysterious man came to their doorstep and claimed to be Little Xi’s father.

Tang Siyu looked at this tall and handsome man, who her son was a carbon copy of, and then became angry.

Five years ago, the bastard who pinned her down was him?

- Description from Novelupdates

When he did not know her true identity, he treated her very badly, he disliked her too much, she was not elegant enough, she was in the way...Only later did he realize that the woman was his legal wife! He repented, tried to recover her feelings, but she was determined to divorce him.