Of course it's edited but speaking as somebody who brought up (only) three children on a farm in the middle of nowhere I can spot the joins.
You can't make children happy and enthusiastic and the producers are savvy enough to realise we've all had a gut full of spoilt, whingeing, miserable kids, bleating about how unfair everything is and speaking rudely to their parents.
You only have to look at their confidence and consideration towards others to know that any grumbles, sibling fall outs etc., would be pointless viewing.