Here is a picture of a slender framed woman, from behind, with a Desantis OWB SOB holster. Her pistol is dimensionally larger than the PT111 you're holding in your picture, so the corresponding holster would be smaller (and flatter)....

Here's a galco version of the same idea:

And lastly, here is an IWB version of an SOB holster from D.M. Bullard:

The D.M. Bullard holster has the advantage of having a slot for an extra magazine. Of course, all of these are available for a number of different pistol brands/models/sizes, and most reputable manufacturers offer some kind of SOB holster, so you would have to do some research, but this might be a viable alternative to consider.
My last piece of advice, for what it's worth, is to build your carry method around your gun choice, and not the other way around. Pick the gun first, for its various virtues that matter to you (i.e. the best combination of weight, caliber, size, and capacity that makes sense to you), and then pick the means to carry it. Since there are lots of different carry options for almost every kind of pistol made, I think you'll find this approach less limiting without decreasing your protection options.
OTH, the gun you carry with you beats the one you left at home.