Children's needs, feelings and wishes are always considered important in mediation, whether they are present at a session or not.
Parents and not their children make decisions about child related matters. However, parents need to give due weight to their child's views subject to that child's maturity and understanding.
If you both believe it appropriate, I may see your children if they are old enough and if it would be helpful for them to communicate their thoughts and feelings directly to me.
I would then send a letter to each child to ask them whether they wish to attend. I would see your child or children separately and then I or your children would tell you what they said to me.