Write from facts rather than momentum
Pause long enough to remove accusations, assumptions, and details that belong to someone else. For a message about how to invite an estranged relative to a memorial, use this factual base: give the event, date, location, relevant history, and what kind of contact the invitation involves.
Offer a proportionate next step
Match the size of the request to the relationship and to what the recipient can reasonably decide now. Offer a simple way to accept, decline, ask a practical question, or choose a lower-contact option. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Protect privacy on both sides
Do not announce their attendance, use relatives to persuade them, or make a public gesture before they agree. Respect no-contact, venue safety, custody, and legal restrictions even when the event feels important. Use the most private legitimate channel available and do not share the exchange to recruit support or pressure.