Did your niece KNOW you were armed, or did she just start kicking your ass and hit the jackpot?
I am not saying it's impossible for someone to get your gun from your holster, what I am saying is that your reactions to your niece getting close to you should be very different from a arranger getting close to you.
I also bet your niece could have gotten your gun no matter what kind of holster you were using.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.