The Miscalculations of Lightning Girl, by Stacy McAnulty

When she was eight years old, Lucy was struck by lightning.  As a result of the experience, she suffered permanent brain damage that gave her unusual mathematical skills.  For the past four years, she's been homeschooled, mastering all of high school math and most of college-level as well.  At twelve, she feels ready to go away to study at a university.  However, her grandmother (and guardian) isn't so sure.  She feels that Lucy needs to spend more time with her peers and challenges Lucy to mainstream and return to middle school.  If Lucy can make it through a year, make at least one real friend (on-line math buddies do not count), participate in an activity, and read a book about a non-mathematical subject, grandma will consent to Lucy's promotion.

For Lucy, middle school is an unsolvable equation.  Between her long  absence from socializing to her issues with OCD (another side effect of the lightning strike), middle school is particularly challenging.  But with some bravery, Lucy figures out a way to navigate seventh grade, even if it involves making a fair share of mistakes along the way.

A winning story of friendship (with all of its messy foibles) and of a girl who tackles the unpredictable world of real life adolescence.  There are some tear jerking moments of animal peril, but the story is mostly about Lucy sorting out the unpredictable nature of the social humans.  It's a storyline without particular surprises, but that makes it no less enjoyable.  Lucy's bravery with stepping outside of her comfort zone is inspirational.