Books that are about "the girl"

I noticed at Barnes and Noble that a ton of books are about "the girl". Who is she?
  1. Beware that girl - Teresa Toten
  2. The Danish girl - David Ebershoff
  3. The girl from everywhere - Heidi Heilig
  4. The perfect girl - Gilly Macmillan
  5. The girl with the dragon tattoo - Stieg Larsson
  6. The girl with the lower back tattoo - Amy schumer
  7. The girl on the train -Paula Hawkins
  8. Gone Girl - Gillian Flynn