Treat Ooni 3 like any regular barbecue. A lot of families with young children have posted images of them enjoying their Ooni 3, including Kristian and his son as you can see here.
Ooni 3 by Ooni does get hot to touch but the heat does not transfer through the legs to the table. Children and pets should not be left unsupervised with Uuni 3 while it is lit.