Instead of the trigger pulls, I'd start with other likely sources. Low and left for a right handed shooter is classic "milking," with the "holding fingers" convulsing sympathetically with the pull of the "trigger finger." It can exist separately without trigger jerk, or with trigger jerk, which of course exacerbates it.
Try her for a while with a hard crush grip, exerting maximum force with everything but the trigger finger. While doing so, she wants to be consciously working on evenly distributing trigger pressure straight back with her dominant hand index finger.
Give that a try, please, and get back to us here and let us know how it works out.