Start with the part that is verifiable
Separate the event you can describe from the motive or reaction you are guessing. For a message about how to limit an unsustainable family caregiving role, use this factual base: identify the visit, topic, money, photo, event, care task, or comment that needs a limit.
Make one answerable request
Give the recipient one concrete question or next step instead of several emotional jobs at once. State what is allowed, what is not, and how you will respond consistently. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Leave the recipient in control
Do not threaten access to children or elders as punishment, and do not debate the entire family history. Use safeguarding, legal, domestic abuse, or emergency support where safety, custody, or coercive control is involved. A clear message remains useful even when the answer is no or no answer arrives.