Bearded dragons make good, affectionate pets for responsible owners, and although they are not considered especially dangerous, they're reccomended for older children, because they can be tricky to care for.
Bearded dragons are a territorial lizard. They're not a dangerous pet to keep around smaller children but you have to keep a close eye on the child to make sure its not pulling the lizards tail or legs that can cause the lizard to bite.
My daughter got a bearded dragon for her 8th or 9th birthday. Like all lizards, if you don't handle them regularly they lose their socialization, but its pretty easy care.
The heating, lighting, and dietary needs need to be met. Somewhat expensive to set up at first but they are friendly. Kids need to practice good hygiene to prevent salmonella.