For a SD revolver, unless your wife has a physical impairment, do not mess with the springs - 'smith or no 'smith.
Get some snap caps and have her dry fire until the cows come home. It'll smooth out the action (if it even needs smoothing out) and it will increase her strength. Also have her strengthen her hands/fingers with a stress-ball.
"With great power, there must also come great responsibility." - Stan Lee
"All that is necessary for evil to triumph is for good men to do nothing." - Edmund Burke