What do you mean by "stiff", recoil? Maybe a 380 would work for her. Do you have a range close that rents guns? Ergonomics also play a part in felt recoil. A gun that better fits the hand will have less felt recoil. Weight is always a factor. The lighter any gun is, the more its going to be felt. HK claims less recoil due to their spring design.

I can guarantee you that I can shoot your current gun, and the recoil I feel will be different from the way you perceive it.

Free Recoil Energy is really kinetic energy and so can be expressed mathematically as -

F.R.E. = lrMVz

Where -

M = is the mass (or the weight of the firearm divided by 32.17) and

V = is the velocity of the recoiling firearm,

To determine the velocity of the recoiling firearm we can use the formula:

V

Wo*Vu *W o'*V "

7000xW "

Where -

W" = Weight (in grains) of the ejecta (bullet or shot and wad column)

V" = Velocity of ejecta in feet per second

Won = Weight of propellant gases

Von = Velocity (fps) of propellant gases

7000 = Conversion factor for grains to pounds

W = Weight of firearm in pounds

Handgun Recoil Table