Is It Safe To Have Children Laying And Moving Around On Pregnant Belly?

I would suggest that they play careful around their mothers belly right now. Explain to them that the baby might be asleep. It's a great time to teach them that when the baby comes that it will need tender touching and care.

I wouldn't encourage play on the belly. If the mother is far enough to feel the baby kick, you might get the kids to touch the belly when the baby is active so that they realize that there is something alive in there and that they should be cautious around it.
Lying still on the tummy is probably o.k., my kids did it too. They all laughed when our girl got kicked in the ear. I still laugh to this day about that one. Hope this helps, good luck.

I would think its best avoided ,i don't think laying gently on her stomach would cause problems but rolling and playing kids can be a bit energetic it only takes a hard jolt by accident and it could cause problems if your wife is quite far on