Countingdown has also been digging

Countingdown has also been digging in the archives and pulled up this September 20th, 2000 article from This is London about 3 girls cast in the Harry Potter movie:

Beaconsfield High School pupils Danni Tabor, 15, Natalie Klamar, 15, and Samantha Whittaker, 16, were picked from hundreds of hopefuls.

The three, who also go to Redroof Stage School, Maidenhead, have had letters to say they are in the film. Two of them were called for audition on Friday and asked to perform cartwheels and forward and backward rolls.

Looks like Angelina Johnson and Alicia Spinnet – Gryffindor Chasers on the Quidditch team. Unfortunately, 3rd Chaser Katie Bell is supposedly being played by an “Emily Dale.” This is confirmed by looking at casting news from the Jacke Palmer Agency. Perhaps initial speculations have been incorrect and we’re looking at the 3 chasers from the Gryffindor team or there’s a female Slytherin Quidditch player we’re missing since the book does not list all 7 players of Slytherin’s team. If anyone can find the Slytherin Quidditch Team from Sorcerer’s Stone (year should be 1991) in “Quidditch Through the Ages” do let us know.