There are so many ginger Harry Potter character possibilities with Turner, but she could also play a non-ginger role.
Sophie Turner could play a Weasley, a family member of Lily Evans, and even a third Scamander sibling.
There was only mention of Theseus Scamander (Callum Turner), but maybe down the line a surprise sister will appear in the form of Sophie Turner.
Fantastic Beasts: The Crimes of Grindelwald kind of played fast and loose with the canon Harry Potter storylines, so that opened the world up to do basically whatever with the future of the Harry Potter movies and the Fantastic Beasts world.