Miri and Molly Series by Annie Barrows

Miri is the only single child in the middle of a family with two sets of twins--older brothers and younger sisters. When the family moves to an old farmhouse Miri accidentally travels back in time to 1935 only to discover Molly, a girl in need of a real family to call her own. A very satisfying classic-in-the-making, with spine-tingling moments, this is a delightful family-friendly middle grade time-slip novel.

Miri and Molly were not always sisters, but thanks to the time-travelling magic of their family's home, they are now twins, and about to start settling down to a normal life when the house unleashes another challenge that sends them back into the past. And this time around they've got twice as much to lose ...Brimming with lovable characters and spine-tingling magic, this book will bring new readers to Annie Barrows' highly acclaimed, wonderfully popular world of twin-inspired magic.