A Beretta APX/CZ P10C sized double stack .380 ACP with the S&W Shield EZ style internal hammer and grip safety, but with an HK light LEM style fire control. Ambi manual safety optional.
Interchangeable backstraps for small hands.
Slide has a threaded hole on either side to install a short optional peg or 'charging handle' to assist with gripping the slide to cycle it. VP9/S&W style slide serrations that are slightly wider at the rearmost of the slide as well.
Glock 17/19 style sights and dovetail, Glock style 1913 slot on full-length dust cover that takes Glock keys for most lights/lasers. Factory rear sight will be a nice sharp 90* profile with the slide to assist with one-hand slide cycling techniques.
The pistol would come with a LULA style mag loader or have an exposed follower side-tab like a .22 magazine or the S&W Shield EZ mags to assist with loading.
Anything more than 13-14 rounds would be great, but making the magazine reliable and easy as hell to load takes precedence over raw capacity.
The idea is a near-full-size pistol that has absolutely minimal recoil that can be run safely and effectively by someone with very compromised hand/upper body strength. If it could be done in 9mm, that'd be great, but I'd start with .380 ACP.
Basically, I want an ideal nightstand pistol for people like my buddy's 5ft1in 90lb wife with Ehlers-Danlos who will always have weak hands and joints, or my 71 year old Mother with carpal tunnel and arthritis. Or my old retired 1SG who has minimal use of his left arm from the elbow-down due to a nerve injury, and his right hand has severe arthritis. The only thing worse than seeing him struggle to rack the slide on a Glock 17 was thinking about a man that used to effortlessly one-arm an M240 being left unable to effectively run any available pistol.