Take it to a radiator shop. They can pull the radiator and see if there is a clog or something else.
It could also be the water pump. They occasionally go out, they are what circulates the water. If they go out the water does not circulate and cool down, it sits in one spot and starts to boil.
If you get stranded you need to just let the car cool down then drive it a little further. Do not drive it hot, unless you are at risk you need to just stop. The heat can warp the motor and other metal parts and totally ruin your running ability. If that happens you are looking at a whole new motor and perhaps even more in repairs.
I would have most likely just called home and had someone come get me and the kiddo. Then if you have AAA or some other towing insurance have it towed to the nearest mechanic.