MTL - Xiling Empire - Chapter 10 Advent of the Legion?

Witnessing her boyfriend cheating on her with her bestie, Shiyao was so angry that she went to a pub for fun and met a man, who was really a piece of work. After a crazy night she fled away, but was embarrassed to know that the man she slept with was her boss You Ze.
Jesus, give her a break!

- Description from Novelupdates

Her original self was a powerful jiangshi who had cultivated for innumerable years. However, when she attempted to unlawfully enter the world of the immortals, she was discovered by the Jade Emperor and thrown into the mortal world as punishment. Her soul then left her corpse, fusing with the body of the Motian Dynasty’s sixth princess. She didn’t even have a chance to fully comprehend her current circumstances before her maid unexpectedly ignored her mistress, even publicly provoking her!

“What? That weak and cowardly idiot who has neither her father’s love or mother’s favor actually mistook her older sister as her maid?! All the royal princes in the world loathe her?”

“Damn you! This old lady will let all of you understand why the flowers are so red!”

“Hey! Did you hear? That cowardly sixth princess unexpectedly snatched away the man that the eldest princess favored today!”

“How is that interesting news? That fourth princess who ran always ran amuck in the capital city is now confined to her bed now!”

The good-for-nothing counterattacks! The previously cowardly and incompetent sixth princess suddenly reveals her exceptional talents! She is full of radiant elegance, and unparalleled disdain!

She is driven by the desire to shed no more tears! However, if she had known what would happen later, she would have been better off acting stupid! She had calculated thousands, tens of thousands of scenarios, but had never calculated one where one day, her own prey would unexpectedly turn around, and ruthlessly bully her instead! Damn it, she still hasn’t sucked any blood yet!

- Description from Novelupdates

The queen’s essential feature is this: [must be a woman or a feminine-looking man].

“Married rich for three years with no child born. Just when she was finally cured of infertility and ready to give him a child, he brought home his pregnant mistress in high profile.