The Duprasi I looked after was the most docile creature I have ever owned! He didn't show the same curiosity as a mongolian gerbil and was quite content to just be held and stroked. He was so very slow and docile that a young child should have no problems - in fact probably better than a hamster in that respect.
They can vary quite widely though, and I have heard that some can be very aggressive so it would be important to make sure you found the calmer ones! They are best kept alone from what I've hard as they can be extremely aggressive towards each other, biting at each others tails and even shrieking.
They sleep on their back which is incredibly cute, and they are very easy to care for. Its important they get a sand bath to prevent their fur getting greasy and they have a simple diet not that different from a mongolian gerbils. The only downside to them personally (providing you get a calm one!), would be that they are not actually that interesting to watch as they do tend to sleep a great deal, other than when you are of course!