The "Harry Potter" star will be back on screens playing Millie Bobby Brown's titular character's mother Eudoria Holmes in the sequel to the 2020 action-adventure flick.
According to The Wrap, "Chewing Gum" actress Susan Wokoma is also reprising her role as Enola's jiu-jitsu teacher Edith.
New cast members include another "Potter" actor, David Thewlis, and "Dune" actress Sharon Duncan-Brewster, plus "Harlots" star Hannah Dodd, "Twilight Zone" 's Abbie Hern and "Endeavour" 's Gabriel Tierney.
None of the newcomers' roles have been revealed by Netflix at this time.
Henry Cavill will also reprise his role as fictional detective Sherlock Holmes and Louis Partridge will be back as Enola's on-screen partner-in-crime, Tewkesbury.
Harry Bradbeer is once again taking to the helm of the second movie in the mystery franchise.
The premise for the sequel reads, "The adventure continues as Millie Bobby Brown and Henry Cavill return to the world of Enola Holmes, reteaming with director Harry Bradbeer and writer Jack Thorne on a second film based on Nancy Springer's book series about Sherlock Holmes' brilliant sister."
Millie previously said, "I can't wait to collaborate again with my Enola Holmes family. Enola holds a special place in my heart - she's strong, fearless, intelligent and brave. I look forward to fans seeing how her journey continues!"
The original film was based on "The Case of the Missing Marquess" by Nancy Springer.