fmj Get you a bike innertube. One from a skinny tire bikes and start cutting pieces one bigger than the one before . Start at a 3/8", 3/4" 1 1/9" and so on and place one over the other on the grip. You can find a combo of width and thickness that will help to give your lady some grip and fill her hand better than stock. She may not carry that way but it does work to help get comfortable with a new small pistol.
i carried a pf-9 for 2 1/2 years with zero issues but sold it after buy'n a used kahr cw9 and now carry a cm9. Just a smoother shooting pistol.