Archive of Our Own (AO3) is a good place to start. It has a wide range of fanfiction, and you can search for Lysa Arryn - related works there. Just be sure to use the correct tags.
There are also some smaller, niche fanfiction communities or forums dedicated to the series that Lysa Arryn is from. These can sometimes be a goldmine for finding unique and interesting fanfictions. You can try searching for those specific to the world she belongs to, and then look for works related to her character. But be aware that the quality and content can vary greatly in these smaller communities.
Chapter 26 is the strongest chapter-level answer because it starts from Shen Lan was bent over processing a large stack of press briefs on her... and follows through on If you think you can use our family connection to have me handle this....
A practical answer is Chapter 29, because it turns the idea into a concrete scene. The chapter opens with Big brother, it's me..." The shadow suddenly spoke and it was Jiang..., adds pressure through Learning from experience, Jiang Yan chose to stand next to Lin Manru this..., and ends on Big.
Chapter 35 is the strongest chapter-level answer because it starts from Shining Transformation Trip's filming location was set on the distant... and follows through on Brother is really hardworking, actually arriving at the same time as the....
Chapter 61 is the strongest chapter-level answer because it starts from Hahahaha, oh my god, Jiang Li's mouth is even more venomous. and follows through on A cold shower is pretty normal, right?.
A practical answer is Chapter 29, because it turns the idea into a concrete scene. The chapter opens with Big brother, it's me..." The shadow suddenly spoke and it was Jiang..., adds pressure through Learning from experience, Jiang Yan chose to stand next to Lin Manru this..., and ends on Big.
Look to Chapter 26 for the clearest answer. It begins with Shen Lan was bent over processing a large stack of press briefs on her..., keeps building through She was nearly forty years old, but because she took good care of herself..., and lands on If you think you can use our family connection to.
Look to Chapter 25 for the clearest answer. It begins with Therefore, from his childhood, Jiang Shixu had felt an extreme aversion to..., keeps building through Over time, he naturally developed a gap of estrangement between himself..., and lands on Having worked beside Shen Lan for over a decade.
A practical answer is Chapter 32, because it turns the idea into a concrete scene. The chapter opens with You should know, an ID photo is like a mirror for demons., adds pressure through This time, we bring six guests to travel to the distant Highland Mountain..., and ends on With airflow comes.
The best chapter pointer here is Chapter 67, "You Can Still Pick Mushrooms?!". It opens with I'm pissed," Jiang Yan cursed again, "These people are too much, aren't... and closes on Accompanied by the wisps of smoke gradually rising from the stove behind....
The best chapter pointer here is Chapter 64, "The Morning Battle". It opens with Chixia Village lay in tranquil slumber. and closes on He'd been a host for so many years; he was used to it..