By L. M. Montgomery
Two aging siblings send away for an orphan boy to help on the farm and get a red-haired, motor-mouthed girl instead — and she wins them over completely.
Matthew and Marilla Cuthbert are getting on in years, so they write to the orphanage for a quiet boy to help run their farm, Green Gables, on Prince Edward Island. What gets off the train instead is Anne Shirley: eleven years old, red-haired, skinny, and completely unable to stop talking. It's a mistake, and they mean to send her back. But Anne christens the cherry tree the Snow Queen and the pond the Lake of Shining Waters, falls head over heels for every inch of the place, and somehow she stays. Most of the book is a string of scrapes: she cracks her slate over Gilbert Blythe's head for calling her Carrots, accidentally gets her best friend Diana drunk on what she swore was raspberry cordial, dyes her hair a ghastly green trying to turn it black. Underneath the comedy, two settled, particular old people slowly come to love this odd, dramatic girl as their own.
This is a genuine 1908 classic, so the prose is old-fashioned and the chapters run long, and Anne herself is why a child keeps turning pages anyway. She's so alive and so funny that the density stops mattering. It's also a gentler climb than it looks, because the story comes in episodes: one scrape, one triumph, one embarrassment at a time, so your child can read it in comfortable stretches rather than carry a big plot in their head. Stick with it and the reward is a slow-built family that a lot of readers never quite get over.