As an extension to this question, my daughter was very relieved when I offered to talk to my family for her. My husband thought of having a brunch with our kids not in attendance. I thought of doing an online meeting (Zoom etc.).
Now I've come around to the idea of simply sending out letters. The benefit, as I see it, is that it gives every family member a chance to react without being observed by us or others, since their reaction may not be immediately supportive. It gives family a chance to digest the information before they interact with us again, and the power to choose when they are ready to interact.
However, it also strikes me that this could be taken as a very cold and distant way of disclosing very important information.
In our case, "family" is only 6 people (her father's an orphan). There's just my parents who live with my sister and brother-in-law, and my brother and sister-in-law who live about 5 minutes away from them.
Question: How could I disclose my daughter's new gender identity without sounding cold or distant?