Episode Summary
Zou Yiniang influences Shen Jiangli's father to marry Qilan off to Lu Jingming, but Qilan is in love with Lu Jingxiu. Shen Jiangli tries to help her sister. At a banquet, Shen Jiangli reveals Qilan's love for Lu Jingxiu, leading to Lu Da Lǎoye agreeing to Lu Jingxiu taking Qilan as a concubine, much to Wang Danling's dismay. Qilan expresses her loyalty to Wang Danling, but is rejected.

Spoiler Alert
"My Destined Consort" Episode 13: Drama Alert!
So, things are heating up in "My Destined Consort"! In this episode, Shen Jiangli's stepmother, Zou Yiniang, gets some ideas planted in her head by Danling Popo (probably some gossipy elder), and starts whispering in Shen Jiangli's father's ear. And wouldn't you know it, the dude's a pushover! He immediately agrees with whatever Zou Yiniang is suggesting.
Turns out, Zou Yiniang wants to marry off Qilan (Shen Jiangli's sister) to the Second Young Master, Lu Jingming. Qilan is NOT having it. She tries to explain that she's not interested in Lu Jingming at all, and that her heart belongs to someone else. But Dad's not listening to a word she says.
Naturally, Qilan freaks out and runs to her sister, Shen Jiangli, to spill the tea. Shen Jiangli is all ears and asks who this mystery man is. When she finds out it's Lu Jingxiu, she's shocked! Lu Jingxiu's wife, Wang Danling, is no joke, and her family is super powerful. Shen Jiangli knows that if Qilan becomes Lu Jingxiu's concubine, she's in for a world of trouble. But Qilan is head-over-heels for Lu Jingxiu himself and says she'd be happy just to be near him.
Shen Jiangli, bless her heart, sees how much Qilan loves Lu Jingxiu and decides to play matchmaker. She starts plotting to create an opportunity for them. Soon enough, at Lu Jingming's father's birthday banquet, the First Madam starts pushing the governor to get Lu Jingming a concubine to, you know, continue the family line. She even says how jealous she is of people with sisters.
Wang Danling jumps on this, trying to force Shen Jiangli to agree. But Lu Jingming straight-up says he's never even met Qilan and refuses to take a concubine. Shen Jiangli then drops a bomb: she reveals that her sister Qilan already has someone she loves, and they're deeply in love. To prove it, she pulls out a jade pendant that the guy gave Qilan as a token of his affection. Wang Danling, who was all high and mighty a second ago, suddenly looks like she swallowed a lemon. The jade pendant belongs to Lu Jingxiu! Busted!
So, Wang Danling's plan to stir up trouble in Lu Jingming's love life totally backfires. Lu Da Lǎoye (the head of the Lu family) asks Lu Jingxiu about the affair, and he confirms it! Despite Wang Danling's protests, Lu Da Lǎoye decides that his son needs a concubine to have more children.
Qilan is over the moon that her dream is coming true and can't sleep all night. She even goes to see Wang Danling privately, promising to know her place and serve her respectfully. But Wang Danling isn't even trying to hide her disdain and tells Qilan to get real and stay away from her. Ouch!