Rebirth of an Abandoned Woman - Chapter 7: Lost Marbles

A con-man and policewoman that are legends of their respective professions suddenly die, then are reincarnated and return to the Tang Dynasty of ancient China as little kids.

Accepting their second chance and forced restart, they choose to use the modern knowledge and specific talents that they have in their previous lives in order to live comfortably in this new life.

- Description from Novelupdates

"An accident. She's pregnant. How unlucky. She got pregnant in one shot!

A top-secret experimental explosion transports Xiao Ming to a parallel world resembling ancient times.In this hostile land, he is the most unfavored prince, given the most barren fiefdom.Fortunately, however, a mysterious item from the experiment—the Technology Crystal—comes with him, granting him the ability to upgrade a technology tree.Thus, he begins a leisurely life in his fief, farming and developing industry.In the face of his unfriendly brothers and sisters, he has always followed the motto- friends come and get wine, jackals come and get shotguns.