Pei Jixian grew up by the Empress Dowager's side as a potential consort for the emperor. The Empress Dowager wanted to control the emperor, while Pei wanted to rise above everyone else. They were partners in crime, each with her own agenda.
But before the Empress Dowager could send her off, the current emperor died and was succeeded by Emperor Zhezong.
So Pei and the Empress Dowager hit it off and supported Prince Duan, the eleventh son of Emperor Shenzong, in taking the throne. Prince Duan had been clever and well-behaved since childhood, and his mother had died young, so both women were pleased with him.
Wait, young man, you look so honest and upright... How are you Emperor Huizong of Song?
Zhao Ji: Sister Pei, can I really become emperor?
Pei Jixian: The Tenth Brother is exceptionally clever. How could you not manage it?
After dreaming of the Jingkang Incident that night, Pei Jixian: ...Maybe you shouldn't become emperor after all.
----- The following is the serious version -----
Looking back toward home, three thousand li away, I gaze toward the southern sky, where not a single wild goose flies.
Since the Yuanyou era, political infighting had become rampant, officials were corrupt, factions plotted against each other within the realm, and powerful enemies threatened the borders.
Fortunately, after Emperor Zhezong took power, he employed members of the New Faction during the Shaosheng and Shaoshu periods and struggled to expand the borders. Just as things were beginning to improve, Zhezong died at the age of twenty-three.
How can she mediate factional strife during Emperor Huizong's reign, continue reform, strengthen the country and its military, and expand the frontiers, while preventing everyone from being captured and sent north to fish in the future?
An older woman and younger man romance (even a six-month age gap kind of counts)
A female lead with a Bodhisattva's face but little conscience for anyone but herself and the male lead x a lively little crane fairy who is hard to describe, but acts like a good boy in front of the female lead
The female lead is a native of a parallel world, not a transmigrator. There is both a romance and a plot, with quite a bit of romance. She may rule as regent midway through the story; it takes time to get there. I'm not very good at writing blurbs, alas.
----- The following are warnings -----
The male lead is Zhao Ji. The male lead is Zhao Ji. The male lead is Zhao Ji.
This is not anti-Song; in fact, it's very pro-Song. Bear with it, or don't.
This is broadly a story about a female lead ruling as regent. It is not true history, and it's full of original settings.
The story will not use the dubious historical evidence found only in the unofficial history known as The Jingkang Miscellany.
Theme: Never submit to fate; hold fast to your ideals