There might be. Check fanfiction.net too. Some writers might have been inspired to create a crossover between these two very different universes. However, the quality can vary a great deal. Some might focus more on the comical aspect of Harley Quinn in the magical world of Harry Potter, while others could attempt a more serious take on how their different powers and mentalities interact.
Yes, there are some out there. You can start by looking on popular fanfiction websites like Archive of Our Own. Just search for 'Harry Potter x Harley Quinn' and you'll find a variety of stories, from crossovers where Harley Quinn somehow ends up in the Harry Potter universe and causes chaos, to more complex stories where the two characters' personalities and backstories are intertwined in unique ways.
Chapter 867, "Then what does our child count as?!", is the clearest early answer because it turns Watching Jiang Meng's situation into a concrete plot event. The chapter gives readers a real answer by opening on Lili's brother, Chen Nanyu, was the only ray of light in his dark...
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 53 is the strongest chapter-level answer because it starts from Night had fallen over Chixia Village, eerily void of any human sounds. and follows through on Wait, did this kid accidentally fall into the water?] [Help, this camera....
If you want the clearest chapter reference, go to Chapter 39. Early on, Qi Tianyu had been looking forward to watching Jiang Li's drama unfold.; later, the chapter leans on But to his surprise, Wen Jiaojiao, who seemed to possess some strength,....
A practical answer is Chapter 4, because it turns the idea into a concrete scene. The chapter opens with Qiao regretted her words as soon as they left her mouth., adds pressure through It's difficult for us when you ask for a guest's room number and key right..., and ends on A little girl acting.
Chapter 37 is the strongest chapter-level answer because it starts from The barrage was suddenly filled with hahas, but the two guests present... and follows through on I look forward to your guidance." He Yun nodded slightly, then continued....
Chapter 12 is the strongest chapter-level answer because it starts from Qin?" Jiang Li called out twice, and only then did Mrs. and follows through on The glass shattered on the floor with a crash, attracting the attention of....
If you want the clearest chapter reference, go to Chapter 3. Early on, Qiao was still annoyed at the attitude of this unknown girl when she heard...; later, the chapter leans on She's actually Miss Jiang Li from the Jiang Family?!.
Look to Chapter 41 for the clearest answer. It begins with The live streaming room suddenly boiled over again., keeps building through [Did this matter really have such a big impact?, and lands on In contrast, Wen Jiaojiao didn't have such awareness..
The best chapter pointer here is Chapter 39, "Is This Book an Out-of-Print Buddhist Scripture?!". It opens with Qi Tianyu had been looking forward to watching Jiang Li's drama unfold. and closes on His original intention was just to make Jiang Li back off gracefully,....