Clarify the agreement that existed
Identify the promise, policy, schedule, ownership, or shared understanding that applies before assigning blame. For a message about how to choose a school with a co-parent, use this factual base: state the child's schedule, health, school, expense, or behavior and distinguish observation from interpretation.
Resolve the next dependency
State what is complete, what remains disputed, and which action would move the situation forward. Propose a child-focused plan, a response date, and the documented route for unresolved decisions. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Document without threatening
Do not use the child as messenger, trade access for agreement, or criticize the other parent to the child. Follow custody orders and use safeguarding, legal, medical, or emergency support for risk to a child. Keep a factual record and describe only remedies you are entitled and prepared to use.