First, the strain screws for SB and RB guns are different. If you need one for a RB, I think I have one somewhere, PM me.
Second, replace the mainspring with the factory one (you show one in the pictures) and try it again. That should cure any problems with light strikes.
Third, if the strain screw on your wife's gun wasn't screwed in all the way originally and you screwed it in all the way when you reinstalled it, it's normal that the trigger pull feels heavier. When a revolversmith wants to lighten the trigger pull on an S&W K, L, or N frame, s/he shortens the strain screw to get the desired effect and screws the strain screw all the way in. Simply backing off on the strain screw is considered a bad practice. If your wife feels the trigger pull is too heavy with the strain screw all the way in, and there's a factory mainspring in the gun, try replacing it with the Wolff mainspring from your gun.
ETA: @Malamute - Coke!