.
If it means the MK9 will stay in the drawer and not be carried,
then get the PM9.
If weight does not matter then get the MK9.
These points are really axiomatic as the heavier gun will handle
"better".
But I tell you with full assurance and experience that the Kahr PM9
handles amazingly well, even with +P ammunition. I could hardly
believe it the first time I shot one. The Kahr design is very refined
with a low grip to bore axis. This helps keep the felt recoil pulse very
low. The PM9 was so comfortable to shoot that I ended up getting
a PM40 and a P40 which also handle extremely well for their power
to weight ratio. But I would not recommend them in your case at
this time. Maybe later.
I think if you start your wife out with regular pressure ammo in 90 or
100 grain loadings and work up, she will be in love with the PM9
by the 2nd or 3rd range session, if not the first.
.