As an instructor that had seen dozens of people with your same question/issues. First off you made a good choice in a firearm.

Key words, new gun+wife= need common sense.

1. Screwing with the "lock" is insanity in my opinion. Leave it alone and you will be fine.

2. Try and find some 148 gr. wadcutters to start her out with. They have little recoil and they may prevent her from flinching even worse than she will anyway.

3. Wadcutters can be used for a carry load. There are better options, but putting rounds on target is her first priority.

4. A reasonable carry load would be Speer Gold Dot 135gr. short barrel. Don't worry about the +P part. After practice, and in a SD situation, first shot recoil will be the last of her problems.

5. I have my students shoot the gun single action until they are very comfortable with the recoil. Then go home and with a UNLOADED firearm, dry fire double action until their finger is strong enough to make shooting that gun double action only is second nature.

6. I would definitely invest in a set of Crimson Trace Lasergrips. I find women like the LG305's. That dot will definitely teach her trigger control and in a panic situation, it takes using the sights on your gun out of the equation. Their website will have great videos. Now, she can really put that dry fire practice/trigger control to good use.

7. If you plan on shooting the shorter 38 specials, make sure you thoroughly clean the chambers so you still have the option of using (not a great idea) the .357 rounds if you choose. (that will really help develop a flinch). In fact, I would clean the gun after each use to make things easier. Especially if you are using lead bullets.

8. Practice and more practice. Hopefully with another experienced shooter that can help. Las Vegas has a lot of ranges and any money you spend on instruction would be well spent.

You did good and I wish you and your wife the best. Sorry for the long post but new shooters are my passion.