“My Sister’s Keeper” is an immediate audience-grabber, as we learn that an 11-year-old girl was genetically designed as a source of spare parts for her dying 16-year-old sister. Yes, it’s possible: in vitro fertilization assured a perfect match. And no, this isn’t science fiction like Kazuo Ishiguro’s Never Let Me Go, with its cloned human replacements. It’s just a little girl subjected to major procedures almost from birth to help her sister live.