No character details have been released at this time, though she is more likely to play a fellow museum security guard alongside Ben Stiller than a historical figure. She may have a role similar to Jonah Hill in Night at the Museum: Battle of the Smithsonian.
Other confirmed cast members include Robin Williams, Ricky Gervais, Owen Wilson and Steve Coogan, who all reprise their roles from the previous two movies. The only other newcomer besides Rebel thus far is Dan Stevens, best known for his work on Downton Abbey. He is being set up as the villain, Sir Lancelot of the Roundtable.
While no firm story details have been revealed, the main action will take place in London this time out. Shawn Levy will return from the previous movies to direct from a screenplay by franchise creators Thomas Lennon and Robert Ben Garant.