Many thanks to Has on Twitter for sharing the links.
In short: Two authors were former co-writers. They went their separate ways. One author published a book with only her name on the cover - but it was plagiarised from stuff her former co-writer had written.
From the publisher: https://www.facebook.com/blushingbooks/posts/1077241322314397
From the victim (via her friend's Facebook): https://www.facebook.com/permalink.php?story_fbid=1099645193431519&id=100001581461541
May just be the one book, but in case it's not, beware of solo books by this author.