Mediation vs Court for Modification of Order


My ex and I have a custody order in place. I am the primary custodian of three kids (ages 15, 13 and 8). My youngest was redistricted to a year-round school that began last week. I wanted to appeal the school assignment to keep him in traditional school, but my ex refused to pay any afterschool childcare expenses which would have incurred because the school would not have offered him bus service. Our current summer schedule gives him four weeks in the summer and me five weeks (weeks determined differently in even/odd years). We both agree that the schedule should be modified to acommodate the year-round schedule, but have different ideas on how it should be done. He wants to split the kids up for two of his weeks (having the kids only when they’re off school so that he can have “vacation” time with them). I think he should have all three kids at the same time even if that means having to take/pick up kids from school. I call that “parenting” time. I even told him he could keep two weeks in summer when all three were off and pick his other two from the weeks my youngest is off. No go. He wants to go to see a mediator named in our order for resolving “legal custody” issues. I think it will be a waste of money that I don’t have because my ex never backs down on anything. He has a history of fighting me on everything. What is the probability of a judge splitting up the kids those two weeks?