I don’t imagine she had any role to play. Not in Caesar’s career or Pompey’s.
I’m not a great believer in the old Great Man Theory of History, although JC is as close as you can get. The Roman Republic was doomed. Had been since before Sulla. All of the last century of its life was at least three intertwining battles
Between the Great Families in their quest for rank and prestige (which drove public life) which by definition required the cutting down of any who would take all glory for themselves.
Between Rome and the Italians over extending citizenship
Between the Senate and the ever-swelling economically redundant (because of slavery) mob.
The Marian reforms made the legions the inevitable tool (and later, puppet-master) of those who paid them.
In the face of these titanic forces individuals play out roles or fill niches. Civil War was inevitable as the Republican political system wasn’t able to address the issues.
If Pompey had won the Civil War he and his legions would be in control and it would have been his dynasty that provided the first Emperors. Roman history might have differed in detail following that but it would have followed the same general trajectory.
I’d like a Time Machine to go prevent JC’s killing just to see if see would have gone after Parthia though.