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).
I got this purse for my wife for x-mas and she likes its. She has enough room in it. She likes the hand strap and that it has option to carry as back pack. Also has locks on the pistol pouch, for safety.