It is always an education speaking to a child or siblings group when the parents support them to have their own meeting with a mediator. Generally, children have a lot to say, but sometimes, the meetings last just minutes. It doesn’t matter as long as the child has had the opportunity to say what they want to say and ask what they want to ask.
A recent case I dealt with involved a four year old child. The parents' relationship had not ended well and resulted in police being called to intervene when things spilled over. Luckily, in this situation both parents were able to take a step back and realise the impact that this situation was having on their child.