I see no cause to even stop her. Failing to signal a lane change?? Have never heard 0f anyone getting a ticket for that.
Here's how it works: Cop sees driver, thinks, "Well, there's a scumbag with facial hair and tattoos (or black woman, mexican male that might have drugs, etc.). Guess I better find a reason to pull them over, run their #'s and see if I can catch me a felon." Cop then proceeds to watch for the slightest infraction that would be considered "cause" to pull said driver over. The rest is history.