Did she get ticketed for wreckless or exhibition of speed?

Regardless, how did the cop determine either? Did the cop time the rate of acceleration? Did the drivers break traction? Lose control? Cross a solid white line?

Judge: So officer, how did you determine an exhibition of speed?
Cop: They accelerated really, really fast.
Judge: Did you clock them?
Cop: No.
Judge: Then how did you come to the conclusion that they accelerated really fast?
Cop: It just looked like it.
Judge: Dismissed.

A cop just can't just say "I think they were doing this or that." A cop still needs to have proof or witnesses. A lawyer sees to it.