surfer, has a D been filed yet? i'm sorry your in this situation, but in order to have firm rules in place about who has kids, and when, and then be sure that she sticks to that plan, would be to get a legal order...
i wasn't sure if a D is filed yet or not, but if it is, your L can file a provisional order that will lay down rules on custody, those would remain in effect until the D is finalized before a judge.