Director Christopher McQuarrie shared that her character will be something of a foil to “the core team,” calling her character “a destructive force of nature” that will force the core team to evolve.
We do know, however, that her character will not be friendly to Tom Cruise’s team.
Other than the fact that she’s been training hard and going down slides in her spare time, details about Hayley Atwell’s character are slim at this point.