First: The firearm MUST be carried in a separate pocket. A pocket that has nothing else in the compartment, just the holstered gun. Super important..not just because of the possibility of something becoming lodged in the muzzle or trigger guard but it will always be in the safe position in the pocket, always.
Second: The zippers to access the carry pocket should be ambidextrous and MUST have the ability to lock. The carry pocket is the length of the purse, you can unzip and access from either side. You decide, based on how you want to access the gun. Once you know which side you are using, lock the other side. Why? You never want to grab the gun by the muzzle. Having the ability to lock both sides comes into play when you are at a function where children at present, you may want to lock both sides. This locks out everyone (including yourself), so you decide when you need to do this.
Third: The firearm MUST be holstered and secured to the carry pocket. Placing a gun in a separate pocket is not safe or secure enough. It must be holstered and secured to both sides of the carry pocket, this eliminates the gun turning and due to the weight, it will be butt up in your purse. Because the holster is secured to both sides of the carry pocket, it will always be in the same position all the times.
Fourth: The holster MUST have back straps. These magnetic straps hold the the firearm in the holster. Most holsters are wedged shaped and the gun is "shoved" into the holster. The back straps are an essential component to keep the firearm in the holster. I don't know about you but I toss my purse in the passenger seat when I get in my car nine times out of ten. Being holstered with a back strap and secured to both sides of the compartment, it will not move. Your personal safety and the safety of your loved ones may depend on your firearm being in the same place every time.
These four components are absolutely necessary to carry your firearm in the safest and securest way. All of my purses have these features and the carry system design is the same in every purse. Remember, you're right to carry!