Both my wife and daughter carry 22 caliber 9 shot snub nose revolvers. They don't like the noise or recoil of larger guns, even 32 cal. Both can shoot the eyes out of snake with their little pistols. I feel it is better for them to carry a gun they are comfortable with and accurate shooting, than a larger caliber they hesitate to shoot.
Sound like perhaps they should use hearing protection when they are practicing if that is the only reason they don't like a more effective caliber.