Lost kids

[AndTA]

So, today a girlfriend and I took my daughter and her two kids to a place called Stonefire pizza, which is very similar to Dave and Busters, but for kids- a huge building with one are dedicated to arcade games, a giant playground, rock climbing wall, etc.

We were all at the table finishing up our food when my daughter asked for desert....the place is buffet style so I got up to go get some desert and drink refills for all of us.

When I got back, my friend was running off with her two kids and my daughter, telling me they were going to play...so I went back to the table and enjoyed a few minutes to myself while they played.

A few minutes later my friend comes back and says "Alison walked off and I can't find her" which leads to me and my friend and her kids frantically searching the place for my lost 3 y/o.

About five minutes (and a bucket of my tears) later we finally found her...she had wandered off saying she was looking for me...

Thank god we found her because those five minutes were the worst of my life, and I don't ever want to lose her again! So, for you moms out there, when did you start talking about strangers and what to do if they get lost, etc? What did you tell your young children to do if they get separated from you? Has this happened to anyone, and am I a total jerk for letting her get lost? I feel awful because she keeps telling me she was scared when she couldn't find me and I am sure my hysterical crying when we did find her probably freaked her out even more! Advice?
Any insight would be appreciated!

Thanks- Andrea