First, I should gather information on Uma Ukpai's published works. She has several novellas in the Nollywood series, including "Crumbs of a Child's Life," "Witch of the City," "The Last Sacrifice," and "Mama's Children." These are all novellas published by her, and they're part of the "New Nigerian Novella" series. Are these available as PDFs? Well, since they're published by authors in Nigeria, the availability might be limited to certain platforms. I know that her works are available on Project Gutenberg and some other eBook platforms, but I need to confirm if they are indeed in PDF format. Also, are there updates or revisions to these works? Or maybe the user is referring to an updated edition or a compilation?