Whether they are books, essays, or articles, the word “memoir” implies that the stories written really happened. And so it should be. However, you may run into a problem when the literal facts fail to illustrate the emotions felt. There are times in our lives when a single word spoken just so by a certain person can evoke an incredible emotional response – either positive or negative.
In that situation, I believe it helps the reader to best understand the story if you adjust the facts slightly in order to show the true situation. That should seldom happen if the writer makes the effort to fully recreate the scene as it happened. But there may be the rare exception.
What you can do to protect your reputation for honesty is to include a disclaimer in the front of the book or foot of the essay stating:
Certain situations in this book have been altered slightly
to better portray the actual emotions and actions of that event.
Then the author is on her honor to limit those minor alterations to only those that clarify the reader’s understanding.
What if a family member remembers it differently?
With love and kindness, remind them that it’s fairly common for two people to remember the same event differently. Just ask a police investigator!