Best colubrid for child

Western Hognose. No special requirements and stays small. Will bluff some here and there but very very very rarely ever bite.

wow, he is great!!! I'll check into those. thanks :)

I second the hognose idea. They are good first snakes and if you can handle it before deciding it's even better. Some can always puff and hiss some never will puff or hiss.
You don't need anything larger than a 20l for its entire life, it can live in a ten gallon but that's very cramped for an adult. They take little to no heating. The only downside is once in a while they will go off feeding, but nothing to worry about!
Rat snakes are also a great choice! They also stay pretty small for a long time and they are great to handle. That and who can say no to those big eyes? :-D

Corns...my best guess...good luck pickin' out a colorphase though!

Its already been mentioned, but I'm going to say check into a rosy boa. I have 2, one is a small hatchling and she isn't fast and skittish like some baby corns can be. Plus they are beautiful snakes and the girls will love how soft they are. They also have a great size, adults are about as big around as a corn, but only 3 feet long.

WOW.

No one has mentioned Kingsnakes.

Surprised.

Sub adult Mexican Black Kingsnake, Desert Kingsnake or Bairds Rat snake are all Colubrids worth considering but this is just from personal experience.

Once they grow out of the flighty, skittish stage they ae wonderful snakes to own. All my nieces and nephews from four years old up to sixteen years old reguarly call to see and handle the snakes. Even the younger ones who were apprehensive of the snakes at the start, now can't get enough of them.

well, we can't have corns in GA. :( One of them wants a sand boa, and I think a rosy would be a great choice for her. One wants a milksnake and the experienced one hasn't made up her mind yet (well, she wants a red-tail. sorry, not yet).
I'm so torn, I have promised them the show in GA, but now I hear bad things. It's too expensive to ship, plus the fact that I wanted them to experience the show. We might change and go to a smaller show and see what they find there. You've all made some wonderful suggestions and I have them written down so that when we do get somewhere, I don't forget what you've all said. :)