I'll +1 the M&P 9. I had a Kahr CW9 with some upgrades that I was giving my daughter. She liked it alright, and it probably fit her very small hands better and I know it was far easier to conceal. But when she shot my M&P 9Pro she fired the first round and twisted her head to me with a huge smile on her face and said "I really like this!"
So I explained to her that the differences and advantages of the Kahr for CCW and she still wanted the M&P. We went to H&H and rented some M&Ps (both sizes) and Glocks and she still settled on the M&P full size. So that's what she has now.
But with all that said and in consideration of her arthritis have you considered a Ruger SP101 in .327 Federal Magnum? It's all steel and you can shoot .32 H&R mags or even .32 S&W Longs in it for practice and stoke it with .327s for defense. With .32 longs it should be about like shooting a .22.
So I explained to her that the differences and advantages of the Kahr for CCW and she still wanted the M&P. We went to H&H and rented some M&Ps (both sizes) and Glocks and she still settled on the M&P full size. So that's what she has now.
But with all that said and in consideration of her arthritis have you considered a Ruger SP101 in .327 Federal Magnum? It's all steel and you can shoot .32 H&R mags or even .32 S&W Longs in it for practice and stoke it with .327s for defense. With .32 longs it should be about like shooting a .22.