On my reptile forum, lots of people say the risk is so low/non existent. As long as you wash your hands after handling, there's no worry.
^^ This is really all you need to worry about during pregnancy. Now, I practice careful hygiene with my snakes all the time, so this wasn't really a deal. Just don't lick the bearded dragon and you should be fine. LOL!
As for small kids, my best advice for when they are LITTLE little is to make sure you have an enclosure that is inaccessible. Either in a room the child doesn't have access to (at least not without supervision), or have it be high enough they can't reach. A locking enclosure is a good idea, but not always as easy as it sounds, depending on the containment you choose. That said, even very small kids can learn basic things like "don't pound on the cage" and "that isn't yours, please leave it alone".
I have rack systems for my cornsnakes. They are very secure, but I don't really have any method for locking them. The racks are in the master bedroom, which is an area that Justin generally doesn't spend much time. When I do have him in there with me, well, it's WITH me, so he has direct supervision and I can redirect him if he starts messing around with the racks.
Once the kid is old enough to understand, it's the standard lessons in learning to handle animals with proper respect, including hand washing, etc. Or so I assume. We haven't gotten to that age yet.
All in all, I just practice good keeper habits with my reptiles, and don't stress about it too much.