Mediation - I am autistic and wanting to support my family

Hi,

I'm wondering if anyone can help. I'm exceptionally stressed about trying to support my brother through mediation. My brother is a loving dad and started his child mediation as he was in a very emotionally abusive relationship with his ex-partner. I've tried to find some mediation specific support groups but have found nothing out there. I wondered if anyone had any knowledge regarding this subject. 

Specifically I wanted to know if professional mediators are aware and can identify lying in sessions. My brothers ex-partner was reluctant to go through mediation but unless she wanted to prevent him going to court she has agreed. She is very manipulative and has been telling many lies to the mediator since the sessions began. I find it hard to detect liars but from mutual friends, the conversations that I have had with my brother and the abusive 'paper trail' she has left I have a thorough understanding of what is going on. All my brother wants (as we do as a family) is that his son, my nephew, has the most stable upbringing possible. We also want the emotional and abusive behaviour of my brothers ex to cease. In his documentation that he has prepared for the mediation process he has also stipulated that any contact between himself and his ex will be through a third-party unless there are extraneous circumstances.

I am finding this exceptionally hard and stressful. All I want is for my nephew and brother to be happy. Just to add that my brother isn't seeking to 'gain' custody of his son.

Any advice would be welcome. Thank you.