Here is the cold hard truth. IMO. If she will not be able to remember she is carrying a loaded weapon, or is afraid of having to use it, then she is not ready for it. She will either get herself into serious legal trouble, or she will hesitate to use it when / if she needs and will get herself injured or worse. When you present a weapon you HAVE to be be ready to use it no matter what without hesitation, because you automatically escalate any situation to max danger level. In the words of old, he /she who hesitates first, dies first.
As far as Tasers go, they are not legal in all jurisdictions, and in many are considered a firearm because they shoot a projectile. Some jurisdictions require CC permits for tasers. If you go that route you need to understand the laws behind tasers in your areas. Also, taser are restricted in the same manner as firearms and are not allowed. If she wont remember a firearm, how will she remember a taser. ? If she is not capable of all this, get her a pepper spray fogger , teach her how to use it properly. Not everyone is ready for or capable of handling the responsibility that comes with carrying a concealed weapon.
Also, her not being able to produce quick follow up shots has nothing to do with her stauture or being a woman. It means she needs more training and practice. There are scores of small framed women sho shoot big bore handguns just fine. That is a self defeatist attitude on both your parts. She can do anything she puts her mind to.
FNP-45 Little Girl Big Gun 45ACP Girl shooting 45 - YouTube
Small Girl, Huge Gun - YouTube
Small Girl, Huge Gun - YouTube
McKenzie - 11yo Girl at Shooting Range #3 of #3 - YouTube
Why all the videos? If these girls can shoot competition while moving or just a huge piece of iron, your fiancee can learn to handle a 9mm. Positive attitude, positive reinforcement, and practice practice practice.
Shoot straight, shoot often