A: Ffs you two are grown adults. Shut the hell up. This is the tenth time I’m tell you two, there will be no warning next time and I will personally make sure both of you stay quiet for the rest of the day
B: Boo we have rights!
A: you better exercise the right to remain silent, or else -- Anon Guest
Some parental threats have no weight. Themes like "I will turn this vehicle around," are empty. Void. Children know that the adult in charge wants to get to the destination and therefore the fight in the back seat continues, though at some reduction of volume.
For the siblings fighting in the carriage on the road to Andersyll, the threat of "be quiet or I'll make you quiet," carried a lot more weight. Their father was a mage of some significant power, and there was no doubt that there was a spell for that. Neirogh the Vexed had a spell for everything. Including making sure that his two sons behaved themselves like civilised beings.
How he managed to sire a natural Rogue and a talented Druid was something even his spells couldn't unriddle. Nevertheless, they had become fine young adventurers... and their capacity for being pains in a parental's buttocks had only grown with them. Blade, the Druid, grinned and said, "I'll commune with nature on the roof for a while."