The Puzzling Fate of Millicent Graves by Dora M. Mitchell

Twelve-year-old Millicent Grave's life is a mess. After her mom sank all their money into a fancy fish tank business, her family had to move to an apartment with three creepy landladies.

Then fate (or, actually, the Fates) leads Millie to discover a room full of jigsaw puzzles that give her the power to fix the imperfections in everyone she knows. Soon, her sister is sensible instead of gross, and her mom is successful instead of unlucky. Dad still needs some work, and her new neighbor and classmate Sam Smolt is still annoying—but he’s kind of becoming her best friend anyway.

And if there are mysterious new cracks in the universe in the exact shape of those puzzle pieces, that’s not a problem, right? It’s not like all of reality is about to unravel. Right? . . . Right?