This is a great topic for discussion, and a very important topic since you dont really hear this discussed many places. I have two small children, so I am sort of "in the mix" when it comes to this area and it is something I continually think about.
I have come to the conclusion that I and my kids are probably the most vulnerable to attack in a parking lot or perhaps a park or similar setting.... And in that case, basic rules for parking lot/open area survival apply. Like, Bulldog pointed out.... awareness is the biggest key to survival, or at least your best way to increasing your odds. I try to do everything in my power to keep my head on a swivel and try to find the threat before it finds me. Parking further away in the parking lot where there are no other surrounding cars can also help this. Also, if we are out at a store that has shopping carts, then the kids are in the shopping cart the entire time or my wife is in charge of carrying the kids and/or holding kids hands..... at least that way my hands are free and movement is not hindered in anyway.
We talked briefly on a past thread about parking lot safety with small kids.....
http://www.downrange.tv/forum/index.php?topic=4732.0..... with the focus being on the buckling and unbuckling of kids in car seats in the parking lot. This is a death trap, and its a time when you really have to stay focused in order to not let yourself be sucked into what can be a major blind spot. Each vehicle is different, but you really need to find a method that will allow you to either buckle up your kids from inside the locked car or a method of being able to still survey the parking lot while buckling them up "in the blind". You just have to fight the urge and keep your head outside the vehicle and keep looking around as you get them in their seats.
Luckily, I atleast have the option of bringing a gun to the fight. In your particular case, I think you need to probably see what other weapons (Knives, baton, spray, etc) you can legally carry that may atleast give you some type of advantage in an all out fight or atleast give you a chance to flee