How could Lady Sif fit into the Harry Potter story in a fanfiction?

Chapter 670, "Sister Will Support You", is the clearest early answer because it turns Bai Lu's situation into a concrete plot event. The chapter gives readers a real answer by opening on Jiang Li, sensing that something might have gone wrong, quickly used...

Chapter 485, "Straight On Clash!", is the clearest early answer because the buildup finally cashes out in a real clash.

Chapter 776, "Sister Li Keeps a Toy Boy?", is the clearest early answer because it turns Toy Boy's situation into a concrete plot event.

Chapter 813, "She Has a Child?!", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event.

A practical answer is Chapter 2, because it turns the idea into a concrete scene. The chapter opens with On the top floor of the Financial Building, a gathering of dark clouds..., adds pressure through In my opinion, Mother should kick out this troublemaker who's a stranger., and ends on Jiang.

Chapter 570, "A Simple Auto-Attack Baits Out an Ultimate from the Enemy", is the clearest early answer because the buildup finally cashes out in a real clash.

Chapter 784, "Slander Brother Yang Without Any Proof?!", is the clearest early answer because it turns Mr's situation into a concrete plot event.

Chapter 734, "Are These Primary School Students Arguing?", is the clearest early answer because it turns Brother Jiang's situation into a concrete plot event. The chapter gives readers a real answer by opening on Old Sir Jiang was especially happy.

Chapter 558, "The Love-Struck, Flirty Wife Appears", is the clearest early answer because it turns Luo Xuan's situation into a concrete plot event. The setup is These people's comments are just too unpleasant;

Chapter 567, "Distant Nephew, Long Time No See", is the clearest early answer because it turns Zhuola's situation into a concrete plot event. Early on, After separating from Jiang Li and the others, Team L headed in the....