Okay, this is a fun little mystery. I looked around in my head and in the ways I usually track down book info, and I can't find a widely known, traditionally published title exactly called 'Keeping 13'. That doesn't mean it doesn't exist — it could be a self-published novella, a limited-run zine, a working title, or even a subtitle tacked onto a longer book — but there's no obvious mainstream author attached to that exact title in the big databases I check mentally (think library catalogs, major booksellers, and the usual online bibliographies).
If you have a copy or a cover image, check the copyright page: the author, publisher, ISBN, and year will usually be right there. If you only have a mention on social media or a forum, it might be shorthand, so try searching for phrases around it (like the character names or a unique tagline). Sometimes titles get distorted in reposts — I’ve seen many cases where a novel gets trimmed to a few words and goes untraceable until someone posts the full cover.
Why could 'Keeping 13' be notable if it exists? Small-press books often become conversation pieces because they tackle edgy topics, have striking design, or get propelled by a viral post. It might also be notable for being a debut, a local favorite, or the seed for a later adaptation. If you can send any extra detail (cover art, a line from the blurb), I’d love to help dig deeper — it’s the kind of bibliophile scavenger hunt I actually enjoy.