Pond, good point on the dog, but I have much less faith in pepper spray.
Buzzcook, have you ever heard of windows? Or hammers and crowbars? Most homes have the former, and many would-be intruders have the latter.
And sometimes the cops take over 20 minutes to arrive - look at the OK single mom incident last month.
In that same example, she had an infant, plus minimal training with the pistol and none with the shotgun, and he had a hammer (for forcing entry) and a knife.
With regard to training:
A. There have been no significant differences reported in results between states where a CCW requires training, and states where it doesn't;
B. It takes a while to train a good shooter, but it takes maybe an hour to train a safe handler and good-enough-until-time-allows-more-training shooter; and
C. OP, who decided YOU had enough training to handle a gun? If your wife wants familiarization and access, who are you to deny it to her?