The nylon/elastic purse holsters that most manufacturers include with the bags are a place to start, but they will not be a good fit for many guns.
Your gun won't "snap in" - these holsters have zero retention. If you tip the holster upside down, the gun will slip out. We strongly recommend getting a kydex purse holster that's molded for your specific gun model, with snap-in retention.
You'll get several loose adhesive velcro sheets with it, so you can attach it however you prefer inside your bag (or any surface).
Very cute back, doesn't have as much of the western detailing that most ccw bags have. It's much larger than I was expecting but that works in my favor because I'm able to use it as a diaper bag as well