I am speaking from the standpoint of someone what goes or tries to go to the range once a week with his wife.
I think that there are a few issues to consider here (easiest first):
1. It is very important to get a good holster or method for her to safely carry the gun. If she has good retention it is better for her and she will feel more confident. You also want her to carry it somewhere where she can not have an accidental discharge and where she can get at it easily. Carrying it in the bottom of a monster purse with multiple hairbrushes and pens and pencils etc, sounds like a recipe for disaster. THere was recently an article in one of the magazines by Clint Smith that talked about mountain lion attacks, If I can find it I will relay his opinions (someone here had mentioned lions tigers and bears). You may also want some type of lanyard for retention in the wild.
2. It is very important for her to practice on a regular basis for several reasons:
First I have noticed that when my wife started to shoot, she would flinch at the sound of each shot. This was at an indoor range with good hearing protection. This has lessened over time. At the range she would usually shoot her .357 with .38 loads. Every once in a while I would load it for her and mix in .38 +ps and .357s (I would let her know that I was doing this). Even with experience she would flinch a little at the more powerful loads. Now think what will happen in a high stress situation when she does not have any hearing protection.
Secondly if she practices she will improve her grip and her automatic responses when she has to do things in a stressful situation. She does not want to pull the trigger and lose the gun, because of her grip or being startled. If she is using a pistol then she also has to worry about limp wristing it and getting an FTE.
Third she needs to be able to automatically fix FTEs with a pistol. Tap and rack. Especially in a high stress situation.
3. DO you want her to carry a Pistol or a Revolver? Although my wife has both, I would not want her to carry a pistol (if and when we go to a state that believes in the US Constitution), if she did not practice regularly with it. She needs to understand how to prevent failures and how to clear them - automatically. If she does not practice, she will not do this under stress. There is also the issue of problems with failure to cycle with a pistol, in a close in attack, such as with a mountain lion, if she is in actual contact. (I believe Clint SMith mentioned this in his article). Maybe she is better off getting an 8 shot .357 if she is not going to practice. This will be much more reliable under stressful circumstances, with out a lot of practice.
BUT get her to practice on a regular basis. "Okay honey - would you like to go shopping on the way home from the range?"
If you do want her to carry the pistol I think V3 would be the best, as some of the folks have previously mentioned.