This really happened
The Family Matters category, in particular, has stimulated lots of questions about fiction/non-fiction/creative nonfiction, since many people have significant life stories they want to share. Most short fiction has some experiential basis, and that gives a piece weight and credibility. Some fiction is heavily rooted in autobiography, and that can fuel a powerful story, too.
We do want stories to read like fiction, and anything we publish is presented as fiction. We would certainly recommend changing details that would allow any real-life people to say, Hey, that character is—without a doubt—me.
Maybe most important: Remember that sticking too tightly to "fact" can limit the larger truth that fiction is able to reveal. Give your story the leeway it needs in order to find its own life.
We look forward to reading your story!